Here is the code for the Drop down Jump Box using JS.
With a GO Button
<form name="Jump" action="">
<select name="Menu">
<option value="">Your Choices</option>
<option value="http://offsite1.com/">link 1</option>
<option value="http://offsite2.com/">link 2</option>
</select>
<input type="button" onClick="location=document.Jump.Menu.options[document.Jump.Menu.selectedIndex].value;" value="GO">
</form>
Immediate Action
<form name="Jump" action="">
<select name="Menu" onchange="location=document.Jump.Menu.options[document.Jump.Menu.selectedIndex].value;" value="GO">
<option value="">Your Choices</option>
<option value="http://offsite1.com/">link 1</option>
<option value="http://offsite2.com/">link 2</option>
</select>
</form>