Script that was working stopped

I have script that does a part price look up from an xml script that was working and has stopped for no reason that I can see.

The function below is hooked to form on a custom record to populate the different price levels for a part on warranty operation

the function looks like this

function showPartData()  {   var varPartNum = document.main_form.custrecord_part_number.value;  var varBaanSalesOrder = document.main_form.custrecord_baan_sales_order_number.value;  var PartDataurl="http://www.newpiper.net/rss_data/partdata.asp";  PartDataurl=PartDataurl+"?BAAN_SALES_ORDER_NUM="+encode(varBaanSalesOrder);  PartDataurl=PartDataurl+"&PART_NUM="+encode(varPartNum);    var response = nlapiRequestURL( PartDataurl )  var xmlText = response.getBody();  var xmlHTTPReq = nlapiStringToXML( xmlText );  var PartDataSet = nlapiSelectNode( xmlHTTPReq, "//*[name()='PartData']" );  var PartCost = nlapiSelectValue( PartDataSet, "//*[name()='REP_COST']" );  alert(PartCost)   nlapiSetFieldValue('custrecord_part_cost', PartCost);  var PartDealerNet = nlapiSelectValue( PartDataSet, "/PartData/REP_DEALER" );  alert(PartDealerNet)   nlapiSetFieldValue('custrecord_part_dealer_net', PartDealerNet);  var PartList = nlapiSelectValue( PartDataSet, "/PartData/REP_LIST" );  alert(PartList)   nlapiSetFieldValue('custrecord_part_list', PartList);  var PartOperator = nlapiSelectValue( PartDataSet, "/PartData/REP_PRICE" );  alert(PartOperator)   nlapiSetFieldValue('custrecord_part_operator_net', PartOperator);  var PartDesc = nlapiSelectValue( PartDataSet, "/PartData/ITEM_DESC" );  alert(PartDesc)   nlapiSetFieldValue('custrecord_part_description', PartDesc);  }