CRM 4.0 Get attribute value from entity's GUID using JScript

Recently I have been asked many times about how to get attribute value from entity's GUID using JScript?
The following code demonstrate how to get a user's internalemailaddress by giving user's GUID.
*It has been modified to support multi-tenent deployment.

alert(GetAttributeValueFromID("systemuser", "09DF2AB7-E16D-DD11-88F3-0003FF884968", "internalemailaddress", "systemuserid"));

function GetAttributeValueFromID(sEntityName, sGUID, sAttributeName, sID)
{
    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\">" +
    GenerateAuthenticationHeader() +
    "  <soap:Body>" +
    "    <RetrieveMultiple xmlns=\"http://schemas.microsoft.com/crm/2007/WebServices\">" +
    "      <query xmlns:q1=\"http://schemas.microsoft.com/crm/2006/Query\" xsi:type=\"q1:QueryExpression\">" +
    "        <q1:EntityName>"+sEntityName+"</q1:EntityName>" +
    "        <q1:ColumnSet xsi:type=\"q1:ColumnSet\">" +
    "          <q1:Attributes>" +
    "            <q1:Attribute>"+sAttributeName+"</q1:Attribute>" +
    "          </q1:Attributes>" +
    "        </q1:ColumnSet>" +
    "        <q1:Distinct>false</q1:Distinct>" +
    "        <q1:PageInfo>" +
    "          <q1:PageNumber>1</q1:PageNumber>" +
    "          <q1:Count>1</q1:Count>" +
    "        </q1:PageInfo>" +
    "        <q1:Criteria>" +
    "          <q1:FilterOperator>And</q1:FilterOperator>" +
    "          <q1:Conditions>" +
    "            <q1:Condition>" +
    "              <q1:AttributeName>"+sID+"</q1:AttributeName>" +
    "              <q1:Operator>Equal</q1:Operator>" +
    "              <q1:Values>" +
    "                <q1:Value xsi:type=\"xsd:string\">"+sGUID+"</q1:Value>" +
    "              </q1:Values>" +
    "            </q1:Condition>" +
    "          </q1:Conditions>" +
    "        </q1:Criteria>" +
    "      </query>" +
    "    </RetrieveMultiple>" +
    "  </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/RetrieveMultiple");
    xmlHttpRequest.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
    xmlHttpRequest.setRequestHeader("Content-Length", xml.length);
    xmlHttpRequest.send(xml);

    // retrieve response and find attribute value
    var result = xmlHttpRequest.responseXML.selectSingleNode("//q1:" + sAttributeName);
    if (result == null)
        return "";
    else
        return result.text;
}