Insert into head:

<script language="javascript" type="text/javascript" >
<!-- hide

function jumpto(x){
 document.location.href = x
 
}

// end hide -->
</script>

Insert jump menu:

<form name="form1">
        <select name="jumpmenu" onChange="jumpto(document.form1.jumpmenu.options[document.form1.jumpmenu.options.selectedIndex].value)">
          <option>Jump to...</option>
          <option value=http://www.blah.com/somepage.php>Option</option>
      </form>