MS CRM Fetch and Retrieve from javascript

This code snippet was writing exactly like recommended in MSCRM SDK 4.09.
I was put it in OnLoad() event of my account form, and in the lookup field(at my example - new_postalcodeid) at OnChange() event I was calling my function.

There is two function that are doing the same work but with different methods.

var authenticationHeader = GenerateAuthenticationHeader();
crmForm.all.address1_city.ForceSubmit = true;

window.GetRegionByIndex_Retrieve = function()  
{  
 
if (crmForm.all.new_postalcodeid.DataValue == null)
{
  crmForm.all.address1_city.Disabled = false;
 crmForm.all.address1_city.DataValue = "";
 return;
}

var lookupItem = new Array;

lookupItem = crmForm.all.new_postalcodeid.DataValue;
if(lookupItem[0] != null)
{
 // Prepare the SOAP message.
 var xml = "<?xml version='1.0' encoding='utf-8'?>"+ 
 "<soap:Envelope xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'"+
 " xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'"+
 " xmlns:xsd='http://www.w3.org/2001/XMLSchema'>"+ 
 authenticationHeader+ 
 "<soap:Body>"+ 
 "<Retrieve xmlns='http://schemas.microsoft.com/crm/2007/WebServices'>"+ 
 "<entityName>new_postalcode</entityName>"+ 
 "<id>"+lookupItem[0].id+"</id>"+ 
 "<columnSet xmlns:q1='http://schemas.microsoft.com/crm/2006/Query' xsi:type='q1:ColumnSet'>"+ 
 "<q1:Attributes>"+ 
 "<q1:Attribute>new_regcityarea</q1:Attribute>"+ 
 "</q1:Attributes>"+ 
 "</columnSet>"+ 
 "</Retrieve>"+ 
 "</soap:Body>"+ 
 "</soap:Envelope>";
 // Prepare the xmlHttpObject and send the request.
 var xHReq = new ActiveXObject("Msxml2.XMLHTTP");
 xHReq.Open("POST", "/mscrmservices/2007/CrmService.asmx", false);
 xHReq.setRequestHeader("SOAPAction","http://schemas.microsoft.com/crm/2007/WebServices/Retrieve");
 xHReq.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
 xHReq.setRequestHeader("Content-Length", xml.length);
 xHReq.send(xml);
 // Capture the result.
 var resultXml = xHReq.responseXML;

 // Check for errors.
 var errorCount = resultXml.selectNodes('//error').length;
 if (errorCount != 0)
 {
 var msg = resultXml.selectSingleNode('//description').nodeTypedValue;
 alert(msg);
 }
 // Display the retrieved value.
 else
 {
 crmForm.all.address1_city.DataValue = resultXml.selectSingleNode("//q1:new_regcityarea").nodeTypedValue;
 crmForm.all.address1_city.Disabled = true;
 }
}
}



window.GetRegionByIndex_Fetch = function (){
if (crmForm.all.new_postalcodeid.DataValue == null)
{
  crmForm.all.address1_city.Disabled = false;
 crmForm.all.address1_city.DataValue = "";
 return;
}

var lookupItem = new Array;

lookupItem = crmForm.all.new_postalcodeid.DataValue;
if(lookupItem[0] != null)
{
 var xml = "<?xml version='1.0' encoding='utf-8'?>" +
 "<soap:Envelope xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'" +
 " xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'" +
 " xmlns:xsd='http://www.w3.org/2001/XMLSchema'>" +
 authenticationHeader +
 "<soap:Body>" +
 "<Fetch xmlns='http://schemas.microsoft.com/crm/2007/WebServices'>" +
 "<fetchXml>" +
 "&lt;fetch mapping='logical'&gt;" +
 "&lt;entity name='new_postalcode'&gt;" +
 "&lt;attribute name='new_postalcodeid'/&gt;"+
 "&lt;attribute name='new_regcityarea'/&gt;"+
 "&lt;filter type='and'&gt;"+
 "&lt;condition attribute='new_postalcodeid' operator='eq' value='"+lookupItem[0].id+"'/&gt;"+
 "&lt;/filter&gt;&lt;/entity&gt;&lt;/fetch&gt;" +
 "</fetchXml>" +
 "</Fetch>" +
 " </soap:Body>" +
 "</soap:Envelope>";

 var xmlHttpRequest = new ActiveXObject("Msxml2.XMLHTTP");
 xmlHttpRequest.Open("POST", "/mscrmservices/2007/CrmService.asmx", false);
 xmlHttpRequest.setRequestHeader("SOAPAction","http://schemas.microsoft.com/crm/2007/WebServices/Fetch");
 xmlHttpRequest.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
 xmlHttpRequest.setRequestHeader("Content-Length", xml.length);
 xmlHttpRequest.send(xml);
 
 var resultXml = xmlHttpRequest.responseXML;
 // Check for errors.
 var errorCount = resultXml.selectNodes('//error').length;
 if (errorCount != 0)
 {
  var msg = resultXml.selectSingleNode('//description').nodeTypedValue;
  alert(msg);
 }
 // Process and display the results.
 else
 {

  // Capture the result and UnEncode it.
  var resultSet = new String();
  resultSet = resultXml.text;
  resultSet.replace('&lt;','<');
  resultSet.replace('&gt;','>');

  var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
  xmlDoc.async = false;
  xmlDoc.loadXML(resultSet);
  var results = xmlDoc.getElementsByTagName('result');
  
  for(i=0;i<results.length;i++)
  {
   crmForm.all.address1_city.DataValue = results[i].selectSingleNode('//new_regcityarea').nodeTypedValue;
  }
   crmForm.all.address1_city.Disabled = true;
 }
}
}