function my_inner()
{
   var html;
   html='<select name=aaa><option value=1>tttt</option></select>';
   document.getElementById('test').innerHTML=html;
}
</script>

<table>
   <form name='ass' method='GET'>
      <tr>
         <td>Examle for innerHTML</td>
      </tr>
      <tr>
         <td id='test'></td>
      </tr>
      <tr>
         <td><input type='submit' name='send' value='Send'></td>
      </tr>
   </form>
</table>
<script>my_inner();</script>