Fejl i UPDATE af MySQL

Hvad er galt med denne update:

<%@ Language=VBScript %>
<html>
<body>
<LINK rel=\"stylesheet\" type=\"text/css\" href=\"../_layout/main.css\">
<%
Set Conn = Server.Createobject(\"ADODB.Connection\")
Conn.Open (\"mes1\")
SQLstmt = \"UPDATE  a_user SET username=\'\"&request(\"username\")& \"\', password = \'\"&request(\"password\")&\"\',  f_name=\'\"&request(\"f_name\")&\"\', l_name = \'\"&request(\"l_name\")&\"\', address=\'\"&request(\"address\")&\"\', zip =\"&request(\"zip\")&\", city=\'\"& request(\"city\")&\"\',email=\'\" & request(\"email\")&\"\',groupid=\'\"&request(\"groupid\")&\"\',levelid=\'\"&request(\"levelid\")&\"\' WHERE userid = \"&request(\"userid\")

response.write sqlstmt
Conn.Execute (SQLstmt)
conn.Close
Set conn = nothing
Set SQLstmt = nothing

response.redirect (\"adm_user.asp\")
%>
</body>
</html>

Jeg får flg. fejl:
Fejltype:
Microsoft OLE DB Provider for ODBC Drivers (0x80040E09)
[TCX][MyODBC]You have an error in your SQL syntax near \'\' at line 1