CRM 4.0 : get UserId, BusinessUnitId, OrganizationId on client-side JScript (WhoAmIRequest)

I'm sure it's in SDK, but to be clear I made it as a JScript function, so you can easly get UserId, BusinessUnitId and OrganisationId from client-side WhoAmIRequest, it's a good example.

function GetCurrentUserInfo()
{
    var SERVER_URL = "http://CRM";
    var xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    xmlhttp.open("POST", SERVER_URL + "/mscrmservices/2007/crmservice.asmx", false);
    xmlhttp.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
    xmlhttp.setRequestHeader("SOAPAction", "http://schemas.microsoft.com/crm/2007/WebServices/Execute");
    
    var soapBody = "<soap:Body>"+
    "<Execute xmlns='http://schemas.microsoft.com/crm/2007/WebServices'>"+
    "<Request xsi:type='WhoAmIRequest' />"+
    "</Execute></soap:Body>";
    
    var soapXml = "<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'>";

    soapXml += GenerateAuthenticationHeader();
    soapXml += soapBody;
    soapXml += "</soap:Envelope>";

    xmlhttp.send(soapXml);
    xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
    xmlDoc.async=false;
    xmlDoc.loadXML(xmlhttp.responseXML.xml);
    
    var userid = xmlDoc.getElementsByTagName("UserId")[0].childNodes[0].nodeValue;
    var buid = xmlDoc.getElementsByTagName("BusinessUnitId")[0].childNodes[0].nodeValue;
    var orgid = xmlDoc.getElementsByTagName("OrganizationId")[0].childNodes[0].nodeValue;

    alert("UserId: " + userid + "\r\nBusinessUnitId: " + buid + "\r\nOrganizationId: " + orgid);

}