ASP.net DropDownList: no refreshing!

<TITLE> WebForm2 </TITLE>
<SCRIPT language = 'javascript '>
Function load (){
Var drp2 = document. getElementById ("DropDownList2 ");
Drp2.innerText = "";
For (var I = 0; I <= drp2.options. length-1; I ++ ){
Drp2.remove (I );
}
Var drp3 = document. getElementById ("DropDownList3 ");
For (var I = 0; I <= drp3.options. length-1; I ++ ){
Drp3.remove (I );
}
Var xmlhttp = new ActiveXObject ("MSXML2.XMLHTTP ");
Var oDoc = new ActiveXObject ("MSXML2.DOMDocument ");
Var state = document. getElementById ("DropDownList1"). value;
Xmlhttp. open ("POST", "webform1.aspx? Id = "+ state, false );
Xmlhttp. send ("");
Var res = oDoc. loadXML (xmlhttp. responseText );
Var naItems = oDoc. selectNodes ("// Market/Table/maName ");
Var idItems = oDoc. selectNodes ("// Market/Table/maId ");
Var item;
Var id;
For (item = naItems. nextNode (), id = idItems. nextNode (); item & id; item = naItems. nextNode (), id = idItems. nextNode ()){
Var nastr = item. nodeTypedValue;