Retrieving the current user information

The new solution uses the Microsoft CRM web services to retrieve the user id, business unit id, organization id and the first, last and full name of the currently logged on user. I have attached a simple test form with the following OnLoad event:

var xml = "" + 
"" + 
"" + 
GenerateAuthenticationHeader() +
" " + 
" " + 
" " + 
" systemuser" + 
" " + 
" " + 
" businessunitid" + 
" firstname" + 
" fullname" + 
" lastname" + 
" organizationid" + 
" systemuserid" + 
" " + 
" " + 
" false" + 
" " + 
" And" + 
" " + 
" " + 
" systemuserid" + 
" EqualUserId" + 
" " + 
" " + 
" " + 
" " + 
" " + 
" " + 
"" + 
"";

var xmlHttpRequest = new ActiveXObject("Msxml2.XMLHTTP");

xmlHttpRequest.Open("POST", "/mscrmservices/2007/CrmService.asmx", false);
xmlHttpRequest.setRequestHeader("SOAPAction", "http://schemas.microsoft.com/crm/2007/WebServices/RetrieveMultiple");
xmlHttpRequest.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
xmlHttpRequest.setRequestHeader("Content-Length", xml.length);
xmlHttpRequest.send(xml);

var resultXml = xmlHttpRequest.responseXML;
var entityNode = resultXml.selectSingleNode("//RetrieveMultipleResult/BusinessEntities/BusinessEntity");

var firstNameNode = entityNode.selectSingleNode("q1:firstname");
var lastNameNode = entityNode.selectSingleNode("q1:lastname");
var fullNameNode = entityNode.selectSingleNode("q1:fullname");
var systemUserIdNode = entityNode.selectSingleNode("q1:systemuserid");
var businessUnitIdNode = entityNode.selectSingleNode("q1:businessunitid");
var organizationIdNode = entityNode.selectSingleNode("q1:organizationid");

crmForm.all.sw_firstname.DataValue = (firstNameNode == null) ? null : firstNameNode.text;
crmForm.all.sw_lastname.DataValue = (lastNameNode == null) ? null : lastNameNode.text; 
crmForm.all.sw_name.DataValue = (fullNameNode == null) ? null : fullNameNode.text; 
crmForm.all.sw_systemuserid.DataValue = (systemUserIdNode == null) ? null : systemUserIdNode.text; 
crmForm.all.sw_businessunitid.DataValue = (businessUnitIdNode == null) ? null : businessUnitIdNode.text; 
crmForm.all.sw_organizationid.DataValue = (organizationIdNode == null) ? null : organizationIdNode.text;