Instr + Mid using Javascript

 <script type="text/javascript">
function Mid(str, start, len) {
// Make sure start and len are within proper bounds
    if (start < 0 || len < 0) return "";
    var iEnd, iLen = String(str).length;
    if (start + len > iLen)
          iEnd = iLen;
    else
          iEnd = start + len;
    return String(str).substring(start,iEnd);
}
function InStr(strSearch, charSearchFor) {
   
            for (i=0; i < strSearch.length; i++)
            {
                  if (charSearchFor == Mid(strSearch, i, 1))
                  {
                        return i;
                  }
            }
            return -1;
}
            </script>