var ORG_NAME="xteam";
function retrieve(entityName,entityId,attributeName){
    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\">" + 
    "  <soap:Header>" + 
    "    <CrmAuthenticationToken xmlns=\"http://schemas.microsoft.com/crm/2007/WebServices\">" + 
    "      <AuthenticationType xmlns=\"http://schemas.microsoft.com/crm/2007/CoreTypes\">0</AuthenticationType>" + 
    "      <OrganizationName xmlns=\"http://schemas.microsoft.com/crm/2007/CoreTypes\">"+ORG_NAME+"</OrganizationName>" + 
    "      <CallerId xmlns=\"http://schemas.microsoft.com/crm/2007/CoreTypes\">00000000-0000-0000-0000-000000000000</CallerId>" + 
    "    </CrmAuthenticationToken>" + 
    "  </soap:Header>" + 
    "  <soap:Body>" + 
    "    <Retrieve xmlns=\"http://schemas.microsoft.com/crm/2007/WebServices\">" + 
    "      <entityName>"+entityName+"</entityName>" + 
    "      <id>"+entityId+"</id>" + 
    "      <columnSet xmlns:q1=\"http://schemas.microsoft.com/crm/2006/Query\" xsi:type=\"q1:ColumnSet\">" + 
    "        <q1:Attributes>" + 
    "          <q1:Attribute>"+attributeName+"</q1:Attribute>" + 
    "        </q1:Attributes>" + 
    "      </columnSet>" + 
    "    </Retrieve>" + 
    "  </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/Retrieve");
    xmlHttpRequest.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
    xmlHttpRequest.setRequestHeader("Content-Length", xml.length);
    xmlHttpRequest.send(xml);
    var resultXml = xmlHttpRequest.responseXML;
    return resultXml;
}var resultXml= retrieve("systemuser","a37eeb60-54ae-df11-97a3-00155d612b04","fullname");

alert(resultXml.xml);