HTML Code
<form name="jump">
<select name="menu" onChange="location=document.jump.menu.options[document.jump.menu.selectedIndex].value;" value="GO">
<option value="http://www.urlAnda1">Menu1</option>
<option value="http://www.urlAnda1">Menu2</option>
<option value="http://www.urlAnda1">Menu3</option>
</select>
</form>
