diff --git a/dlls/jscript/Makefile.in b/dlls/jscript/Makefile.in
index ffe3ad9f056..3ccfae33c70 100644
--- a/dlls/jscript/Makefile.in
+++ b/dlls/jscript/Makefile.in
@@ -11,7 +11,8 @@ C_SRCS = \
 	dispex.c \
 	engine.c \
 	jscript.c \
-	jscript_main.c
+	jscript_main.c \
+	lex.c
 
 IDL_TLB_SRCS = jsglobal.idl
 
diff --git a/dlls/jscript/lex.c b/dlls/jscript/lex.c
new file mode 100644
index 00000000000..d482999bc3a
--- /dev/null
+++ b/dlls/jscript/lex.c
@@ -0,0 +1,687 @@
+/*
+ * Copyright 2008 Jacek Caban for CodeWeavers
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <math.h>
+
+#include "jscript.h"
+#include "activscp.h"
+#include "objsafe.h"
+#include "engine.h"
+
+#define YYSTYPE
+#include "parser.tab.h"
+
+#include "wine/debug.h"
+#include "wine/unicode.h"
+
+WINE_DEFAULT_DEBUG_CHANNEL(jscript);
+
+static const WCHAR breakW[] = {'b','r','e','a','k',0};
+static const WCHAR caseW[] = {'c','a','s','e',0};
+static const WCHAR catchW[] = {'c','a','t','c','h',0};
+static const WCHAR continueW[] = {'c','o','n','t','i','n','u','e',0};
+static const WCHAR defaultW[] = {'d','e','f','a','u','l','t',0};
+static const WCHAR deleteW[] = {'d','e','l','e','t','e',0};
+static const WCHAR doW[] = {'d','o',0};
+static const WCHAR elseW[] = {'e','l','s','e',0};
+static const WCHAR falseW[] = {'f','a','l','s','e',0};
+static const WCHAR finallyW[] = {'f','i','n','a','l','l','y',0};
+static const WCHAR forW[] = {'f','o','r',0};
+static const WCHAR functionW[] = {'f','u','n','c','t','i','o','n',0};
+static const WCHAR ifW[] = {'i','f',0};
+static const WCHAR inW[] = {'i','n',0};
+static const WCHAR instanceofW[] = {'i','n','s','t','a','n','c','e','o','f',0};
+static const WCHAR newW[] = {'n','e','w',0};
+static const WCHAR nullW[] = {'n','u','l','l',0};
+static const WCHAR returnW[] = {'r','e','t','u','r','n',0};
+static const WCHAR switchW[] = {'s','w','i','t','c','h',0};
+static const WCHAR thisW[] = {'t','h','i','s',0};
+static const WCHAR throwW[] = {'t','h','r','o','w',0};
+static const WCHAR trueW[] = {'t','r','u','e',0};
+static const WCHAR tryW[] = {'t','r','y',0};
+static const WCHAR typeofW[] = {'t','y','p','e','o','f',0};
+static const WCHAR undefinedW[] = {'u','n','d','e','f','i','n','e','d',0};
+static const WCHAR varW[] = {'v','a','r',0};
+static const WCHAR voidW[] = {'v','o','i','d',0};
+static const WCHAR whileW[] = {'w','h','i','l','e',0};
+static const WCHAR withW[] = {'w','i','t','h',0};
+
+static const struct {
+    const WCHAR *word;
+    int token;
+} keywords[] = {
+    {breakW,       kBREAK},
+    {caseW,        kCASE},
+    {catchW,       kCATCH},
+    {continueW,    kCONTINUE},
+    {defaultW,     kDEFAULT},
+    {deleteW,      kDELETE},
+    {doW,          kDO},
+    {elseW,        kELSE},
+    {falseW,       kFALSE},
+    {finallyW,     kFINALLY},
+    {forW,         kFOR},
+    {functionW,    kFUNCTION},
+    {ifW,          kIF},
+    {inW,          kIN},
+    {instanceofW,  kINSTANCEOF},
+    {newW,         kNEW},
+    {nullW,        kNULL},
+    {returnW,      kRETURN},
+    {switchW,      kSWITCH},
+    {thisW,        kTHIS},
+    {throwW,       kTHROW},
+    {trueW,        kTRUE},
+    {tryW,         kTRY},
+    {typeofW,      kTYPEOF},
+    {undefinedW,   kUNDEFINED},
+    {varW,         kVAR},
+    {voidW,        kVOID},
+    {whileW,       kWHILE},
+    {withW,        kWITH}
+};
+
+static int lex_error(parser_ctx_t *ctx, HRESULT hres)
+{
+    ctx->hres = hres;
+    return -1;
+}
+
+static int check_keyword(parser_ctx_t *ctx, const WCHAR *word)
+{
+    const WCHAR *p1 = ctx->ptr;
+    const WCHAR *p2 = word;
+
+    while(p1 < ctx->end && *p2) {
+        if(*p1 != *p2)
+            return *p1 - *p2;
+        p1++;
+        p2++;
+    }
+
+    if(*p2 || (p1 < ctx->end && isalnumW(*p1)))
+        return 1;
+
+    ctx->ptr = p1;
+    return 0;
+}
+
+/* ECMA-262 3rd Edition    7.3 */
+static BOOL is_endline(WCHAR c)
+{
+    return c == '\n' || c == '\r' || c == 0x2028 || c == 0x2029;
+}
+
+static BOOL is_identifier_char(WCHAR c)
+{
+    return isalnumW(c) || c == '$' || c == '_' || c == '\\';
+}
+
+static int hex_to_int(WCHAR c)
+{
+    if('0' <= c && c <= '9')
+        return c-'0';
+
+    if('a' <= c && c <= 'f')
+        return c-'a'+10;
+
+    if('A' <= c && c <= 'F')
+        return c-'A'+10;
+
+    return -1;
+}
+
+static int check_keywords(parser_ctx_t *ctx)
+{
+    int min = 0, max = sizeof(keywords)/sizeof(keywords[0])-1, r, i;
+
+    while(min <= max) {
+        i = (min+max)/2;
+
+        r = check_keyword(ctx, keywords[i].word);
+        if(!r)
+            return keywords[i].token;
+
+        if(r > 0)
+            min = i+1;
+        else
+            max = i-1;
+    }
+
+    return 0;
+}
+
+static void skip_spaces(parser_ctx_t *ctx)
+{
+    while(ctx->ptr < ctx->end && isspaceW(*ctx->ptr)) {
+        if(is_endline(*ctx->ptr++))
+            ctx->nl = TRUE;
+    }
+}
+
+static BOOL skip_comment(parser_ctx_t *ctx)
+{
+    if(ctx->ptr+1 >= ctx->end || *ctx->ptr != '/')
+        return FALSE;
+
+    switch(ctx->ptr[1]) {
+    case '*':
+        ctx->ptr += 2;
+        while(ctx->ptr+1 < ctx->end && (ctx->ptr[0] != '*' || ctx->ptr[1] != '/'))
+            ctx->ptr++;
+
+        if(ctx->ptr[0] == '*' && ctx->ptr[1] == '/') {
+            ctx->ptr += 2;
+        }else {
+            WARN("unexpected end of file (missing end of comment)\n");
+            ctx->ptr = ctx->end;
+        }
+        break;
+    case '/':
+        ctx->ptr += 2;
+        while(ctx->ptr < ctx->end && !is_endline(*ctx->ptr))
+            ctx->ptr++;
+        break;
+    default:
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+static BOOL unescape(WCHAR *str)
+{
+    WCHAR *pd, *p, c;
+    int i;
+
+    pd = p = str;
+    while(*p) {
+        if(*p != '\\') {
+            *pd++ = *p++;
+            continue;
+        }
+
+        p++;
+        c = 0;
+
+        switch(*p) {
+        case '\'':
+        case '\"':
+        case '\\':
+            c = *p;
+            break;
+        case 'b':
+            c = '\b';
+            break;
+        case 't':
+            c = '\t';
+            break;
+        case 'n':
+            c = '\n';
+            break;
+        case 'v':
+            c = '\v';
+            break;
+        case 'f':
+            c = '\f';
+            break;
+        case 'r':
+            c = '\r';
+            break;
+        case '0':
+            break;
+        case 'x':
+            i = hex_to_int(*++p);
+            if(i == -1)
+                return FALSE;
+            c = i << 16;
+
+            i = hex_to_int(*++p);
+            if(i == -1)
+                return FALSE;
+            c += i;
+            break;
+        case 'u':
+            i = hex_to_int(*++p);
+            if(i == -1)
+                return FALSE;
+            c = i << 24;
+
+            i = hex_to_int(*++p);
+            if(i == -1)
+                return FALSE;
+            c += i << 16;
+
+            i = hex_to_int(*++p);
+            if(i == -1)
+                return FALSE;
+            c += 1 << 8;
+
+            i = hex_to_int(*++p);
+            if(i == -1)
+                return FALSE;
+            c += i;
+            break;
+        default:
+            c = *p;
+        }
+
+        *pd++ = c;
+        p++;
+    }
+
+    *pd = 0;
+    return TRUE;
+}
+
+static int parse_identifier(parser_ctx_t *ctx, const WCHAR **ret)
+{
+    const WCHAR *ptr = ctx->ptr++;
+    WCHAR *wstr;
+    int len;
+
+    while(ctx->ptr < ctx->end && is_identifier_char(*ctx->ptr))
+        ctx->ptr++;
+
+    len = ctx->ptr-ptr;
+
+    *ret = wstr = parser_alloc(ctx, (len+1)*sizeof(WCHAR));
+    memcpy(wstr, ptr, (len+1)*sizeof(WCHAR));
+    wstr[len] = 0;
+
+    /* FIXME: unescape */
+    return tIdentifier;
+}
+
+static int parse_string_literal(parser_ctx_t *ctx, const WCHAR **ret, WCHAR endch)
+{
+    const WCHAR *ptr = ++ctx->ptr;
+    WCHAR *wstr;
+    int len;
+
+    while(ctx->ptr < ctx->end && *ctx->ptr != endch) {
+        if(*ctx->ptr++ == '\\')
+            ctx->ptr++;
+    }
+
+    if(ctx->ptr == ctx->end) {
+        WARN("unexpected end of file\n");
+        return lex_error(ctx, E_FAIL);
+    }
+
+    len = ctx->ptr-ptr;
+
+    *ret = wstr = parser_alloc(ctx, (len+1)*sizeof(WCHAR));
+    memcpy(wstr, ptr, (len+1)*sizeof(WCHAR));
+    wstr[len] = 0;
+
+    ctx->ptr++;
+
+    if(!unescape(wstr)) {
+        WARN("unescape failed\n");
+        return lex_error(ctx, E_FAIL);
+    }
+
+    return tStringLiteral;
+}
+
+static literal_t *alloc_int_literal(parser_ctx_t *ctx, LONG l)
+{
+    literal_t *ret = parser_alloc(ctx, sizeof(literal_t));
+
+    ret->vt = VT_I4;
+    ret->u.lval = l;
+
+    return ret;
+}
+
+static int parse_double_literal(parser_ctx_t *ctx, LONG int_part, literal_t **literal)
+{
+    double d, tmp = 1.0;
+
+    if(ctx->ptr == ctx->end || !isdigitW(*ctx->ptr)) {
+        ERR("No digit after point\n");
+        return 0;
+    }
+
+    d = int_part;
+    while(ctx->ptr < ctx->end && isdigitW(*ctx->ptr))
+        d += (tmp /= 10.0)*(*ctx->ptr++ - '0');
+
+    if(ctx->ptr < ctx->end && (*ctx->ptr == 'e' || *ctx->ptr == 'E')) {
+        int sign = 1, e = 0;
+
+        ctx->ptr++;
+        if(ctx->ptr < ctx->end) {
+            if(*ctx->ptr == '+') {
+                ctx->ptr++;
+            }else if(*ctx->ptr == '-') {
+                sign = -1;
+                ctx->ptr++;
+            }else if(!isdigitW(*ctx->ptr)) {
+                WARN("Expected exponent part\n");
+                return lex_error(ctx, E_FAIL);
+            }
+        }
+
+        if(ctx->ptr == ctx->end) {
+            WARN("unexpected end of file\n");
+            return lex_error(ctx, E_FAIL);
+        }
+
+        while(ctx->ptr < ctx->end && isdigitW(*ctx->ptr))
+            e = e*10 + *ctx->ptr++ - '0';
+        e *= sign;
+
+        d = pow(d, e);
+    }
+
+    *literal = parser_alloc(ctx, sizeof(literal_t));
+    (*literal)->vt = VT_R8;
+    (*literal)->u.dval = d;
+
+    return tNumericLiteral;
+}
+
+static int parse_numeric_literal(parser_ctx_t *ctx, literal_t **literal)
+{
+    LONG l, d;
+
+    l = *ctx->ptr++ - '0';
+    if(ctx->ptr == ctx->end) {
+        *literal = alloc_int_literal(ctx, l);
+        return tNumericLiteral;
+    }
+
+    if(!l) {
+        if(*ctx->ptr == 'x' || *ctx->ptr == 'X') {
+            if(++ctx->ptr == ctx->end) {
+                ERR("unexpexted end of file\n");
+                return 0;
+            }
+
+            while(ctx->ptr < ctx->end && (d = hex_to_int(*ctx->ptr)) != -1) {
+                l = l*16 + d;
+                ctx->ptr++;
+            }
+
+            if(ctx->ptr < ctx->end && is_identifier_char(*ctx->ptr)) {
+                WARN("unexpected identifier char\n");
+                return lex_error(ctx, E_FAIL);
+            }
+
+            *literal = alloc_int_literal(ctx, l);
+            return tNumericLiteral;
+        }
+
+        if(isdigitW(*ctx->ptr) || is_identifier_char(*ctx->ptr)) {
+            WARN("wrong char after zero\n");
+            return lex_error(ctx, E_FAIL);
+        }
+
+        *literal = alloc_int_literal(ctx, 0);
+    }
+
+    while(ctx->ptr < ctx->end && isdigitW(*ctx->ptr))
+        l = l*10 + *(ctx->ptr++)-'0';
+
+    if(ctx->ptr < ctx->end) {
+        if(*ctx->ptr == '.') {
+            ctx->ptr++;
+            return parse_double_literal(ctx, l, literal);
+        }
+
+        if(is_identifier_char(*ctx->ptr)) {
+            WARN("unexpected identifier char\n");
+            return lex_error(ctx, E_FAIL);
+        }
+    }
+
+    *literal = alloc_int_literal(ctx, l);
+    return tNumericLiteral;
+}
+
+int parser_lex(void *lval, parser_ctx_t *ctx)
+{
+    int ret;
+
+    ctx->nl = FALSE;
+
+    do {
+        skip_spaces(ctx);
+        if(ctx->ptr == ctx->end)
+            return 0;
+    }while(skip_comment(ctx));
+
+    if(isalphaW(*ctx->ptr)) {
+        ret = check_keywords(ctx);
+        if(ret)
+            return ret;
+
+        return parse_identifier(ctx, (const WCHAR**)lval);
+    }
+
+    if(isdigitW(*ctx->ptr))
+        return parse_numeric_literal(ctx, lval);
+
+    switch(*ctx->ptr) {
+    case '{':
+    case '}':
+    case '(':
+    case ')':
+    case '[':
+    case ']':
+    case ';':
+    case ',':
+    case '~':
+    case '?':
+    case ':':
+        return *ctx->ptr++;
+
+    case '.':
+        if(++ctx->ptr < ctx->end && isdigitW(*ctx->ptr))
+            return parse_double_literal(ctx, 0, lval);
+        return '.';
+
+    case '<':
+        if(++ctx->ptr == ctx->end) {
+            *(int*)lval = EXPR_LESS;
+            return tRelOper;
+        }
+
+        switch(*ctx->ptr) {
+        case '=':  /* <= */
+            ctx->ptr++;
+            *(int*)lval = EXPR_LESSEQ;
+            return tRelOper;
+        case '<':  /* << */
+            if(++ctx->ptr < ctx->end && *ctx->ptr == '=') { /* <<= */
+                ctx->ptr++;
+                *(int*)lval = EXPR_ASSIGNLSHIFT;
+                return tAssignOper;
+            }
+            *(int*)lval = EXPR_LSHIFT;
+            return tShiftOper;
+        default: /* < */
+            *(int*)lval = EXPR_LESS;
+            return tRelOper;
+        }
+
+    case '>':
+        if(++ctx->ptr == ctx->end) { /* > */
+            *(int*)lval = EXPR_GREATER;
+            return tRelOper;
+        }
+
+        switch(*ctx->ptr) {
+        case '=':  /* >= */
+            ctx->ptr++;
+            *(int*)lval = EXPR_GREATEREQ;
+            return tRelOper;
+        case '>':  /* >> */
+            if(++ctx->ptr < ctx->end) {
+                if(*ctx->ptr == '=') {  /* >>= */
+                    ctx->ptr++;
+                    *(int*)lval = EXPR_ASSIGNRSHIFT;
+                    return tAssignOper;
+                }
+                if(*ctx->ptr == '>') {  /* >>> */
+                    if(++ctx->ptr < ctx->end && *ctx->ptr == '=') {  /* >>>= */
+                        ctx->ptr++;
+                        *(int*)lval = EXPR_ASSIGNRRSHIFT;
+                        return tAssignOper;
+                    }
+                    *(int*)lval = EXPR_RRSHIFT;
+                    return tRelOper;
+                }
+            }
+            *(int*)lval = EXPR_RSHIFT;
+            return tShiftOper;
+        default:
+            *(int*)lval = EXPR_GREATER;
+            return tRelOper;
+        }
+
+    case '+':
+        ctx->ptr++;
+        if(ctx->ptr < ctx->end) {
+            switch(*ctx->ptr) {
+            case '+':  /* ++ */
+                ctx->ptr++;
+                return tINC;
+            case '=':  /* += */
+                ctx->ptr++;
+                *(int*)lval = EXPR_ASSIGNADD;
+                return tAssignOper;
+            }
+        }
+        return '+';
+
+    case '-':
+        ctx->ptr++;
+        if(ctx->ptr < ctx->end) {
+            switch(*ctx->ptr) {
+            case '-':  /* -- */
+                ctx->ptr++;
+                return tDEC;
+            case '=':  /* -= */
+                ctx->ptr++;
+                *(int*)lval = EXPR_ASSIGNSUB;
+                return tAssignOper;
+            }
+        }
+        return '-';
+
+    case '*':
+        if(++ctx->ptr < ctx->end && *ctx->ptr == '=') { /* *= */
+            ctx->ptr++;
+            *(int*)lval = EXPR_ASSIGNMUL;
+            return tAssignOper;
+        }
+        return '*';
+
+    case '%':
+        if(++ctx->ptr < ctx->end && *ctx->ptr == '=') { /* %= */
+            ctx->ptr++;
+            *(int*)lval = EXPR_ASSIGNMOD;
+            return tAssignOper;
+        }
+        return '%';
+
+    case '&':
+        if(++ctx->ptr < ctx->end) {
+            switch(*ctx->ptr) {
+            case '=':  /* &= */
+                ctx->ptr++;
+                *(int*)lval = EXPR_ASSIGNAND;
+                return tAssignOper;
+            case '&':  /* && */
+                ctx->ptr++;
+                return tANDAND;
+            }
+        }
+        return '&';
+
+    case '|':
+        if(++ctx->ptr < ctx->end) {
+            switch(*ctx->ptr) {
+            case '=':  /* |= */
+                ctx->ptr++;
+                *(int*)lval = EXPR_ASSIGNOR;
+                return tAssignOper;
+            case '|':  /* || */
+                ctx->ptr++;
+                return tOROR;
+            }
+        }
+        return '|';
+
+    case '^':
+        if(++ctx->ptr < ctx->end && *ctx->ptr == '=') {  /* ^= */
+            ctx->ptr++;
+            *(int*)lval = EXPR_ASSIGNXOR;
+            return tAssignOper;
+        }
+        return '^';
+
+    case '!':
+        if(++ctx->ptr < ctx->end && *ctx->ptr == '=') {  /* != */
+            if(++ctx->ptr < ctx->end && *ctx->ptr == '=') {  /* !== */
+                ctx->ptr++;
+                *(int*)lval = EXPR_NOTEQEQ;
+                return tEqOper;
+            }
+            *(int*)lval = EXPR_NOTEQ;
+            return tEqOper;
+        }
+        return '!';
+
+    case '=':
+        if(++ctx->ptr < ctx->end && *ctx->ptr == '=') {  /* == */
+            if(++ctx->ptr < ctx->end && *ctx->ptr == '=') {  /* === */
+                ctx->ptr++;
+                *(int*)lval = EXPR_EQEQ;
+                return tEqOper;
+            }
+            *(int*)lval = EXPR_EQ;
+            return tEqOper;
+        }
+        return '=';
+
+    case '/':
+        if(++ctx->ptr < ctx->end) {
+            if(*ctx->ptr == '=') {  /* /= */
+                ctx->ptr++;
+                *(int*)lval = EXPR_ASSIGNMUL;
+                return tAssignOper;
+            }
+        }
+        return '/';
+
+    case '\"':
+    case '\'':
+        return parse_string_literal(ctx, (const WCHAR**)lval, *ctx->ptr);
+
+    case '_':
+    case '$':
+        return parse_identifier(ctx, lval);
+    }
+
+    WARN("unexpected char '%c' %d\n", *ctx->ptr, *ctx->ptr);
+    return 0;
+}
diff --git a/dlls/jscript/parser.y b/dlls/jscript/parser.y
index 76681f55696..dc966479b79 100644
--- a/dlls/jscript/parser.y
+++ b/dlls/jscript/parser.y
@@ -1543,9 +1543,3 @@ HRESULT script_parse(script_ctx_t *ctx, const WCHAR *code, parser_ctx_t **ret)
     *ret = parser_ctx;
     return S_OK;
 }
-
-int parser_lex(void *lval, parser_ctx_t *ctx)
-{
-    FIXME("\n");
-    return 0;
-}