demo.htm<script>
function a(){
var strText="" 
var intSelIndex=document.form1.selectyear.selectedIndex 
if (intSelIndex>=0)
{  strText = document.form1.selectyear.options(intSelIndex).value ; 
window.location.href = "t.htm?year=" + strText; 
          }
}
</script>
<form name="form1">
<select name=selectyear>
<option value="1">1
<option value="2">2
</select>
</form>
<input type=button onclick="a()" value="test">t.htm<script>
function get()
{
    var url = location.href;
    alert(url.split("?")[1]);
}
</script>
<body onload="get()">