[ОлегА]

пример на jQuery

<script src="script.js" type="text/javascript">
</script>
<script type="text/javascript">
var urlgo="script.exe?var=1&string=";
var url="script1.exe?var=1&string=";
var strclosesug="close";

$('#list1').change(function(){
    urlgo="script.exe?var="+ $(this).val() +"&string=";
    url="script1.exe?var="+ $(this).val() +"&string=";
});
</script>