Combobox a javascript

<script type="text/javascript"> 
function generate(){
//var titulek = document.getElementById("titulek").value;

if (document.generator.doctype2.selectedIndex = 0){
var doctype = "Generovali jste sablonu XHTML strict";
document.form.code.value = doctype;
}

}
</script>

 <form id="generator" name="generator">
<table> 

</td></tr> 
<tr><td>Doctype:</td>
<select name="doctype2" size="1"> 
<option value="0" selected="selected">HTML 4.01 Transitional</option> 
<option value="1">HTML 4.01 Strict</option> 
<option value="2">HTML 4.01 Frameset</option> 
<option value="3">XHTML 1.0 Strict</option> 
<option value="4">XHTML 1.0 Frameset</option> 
</select>
</td></tr>
<tr><td>Titulek:</td><td><input type="text" id="titulek">


</form>

<div style="text-align:center"><a href="#" class="tlacitko" onclick="generate()" >Vygeneruj šablonu</a> </div>
</div>

<textarea name="code" class="code" id="code" rows="24" cols="70" style="width: 99%"> 
&lt;html>
  &lt;head>
    &lt;title>Příklad&lt;/title>
    &lt;script type="text/javascript">
    //tělo scriptu
    &lt;/script>
    &lt;style type="text/css">
      /* definice stylu*/
    &lt;/style>
  &lt;/head>
  &lt;body>
  &lt;h1>Hlavní nadpis</h1>
    &lt;p>Odstavec&lt;/p>
  &lt;/body>
&lt;/html>
</textarea>