Javascript error:Uncaught TypeError: Cannot read property 'branchei' of undefined

Question

i have this javascript code:

<script type="text/javascript">
    var b=document.update.branchei;
   function selectItemByValue(b, <%=branche%>){

for(var i=0; i < b.options.length; i++)
{
  if(b.options[i].value == <%=branche%>)
    b.selectedIndex = i;
}
 }

 </script>

'update' is the name of the form and 'branchei' is the name of the selectbox.

Answer 1

Try that

 var b = document.getElementsByName("branchei")[0];

Or that

var b = document.getElementsByName("branchei");

ps, why dont jQuery?