How to find roles of the logged-in user in MS CRM 4.0 using JavaScript

Function returns all the roles of the Current Logged-In User.

function GetCurrentUserRoles()
{
 var xml = "" +
 "" +
 "<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>role</q1:entityname>" +
 " <q1:columnset xsi:type="\"Q1:ColumnSet\"">" +
 " <q1:attributes>" +
 " <q1:attribute>name</q1:attribute>" +
 " </q1:attributes>" +
 " </q1:columnset>" +
 " <q1:distinct>false</q1:distinct>" +
 " <q1:linkentities>" +
 " <q1:linkentity>" +
 " <q1:linkfromattributename>roleid</q1:linkfromattributename>" +
 " <q1:linkfromentityname>role</q1:linkfromentityname>" +
 " <q1:linktoentityname>systemuserroles</q1:linktoentityname>" +
 " <q1:linktoattributename>roleid</q1:linktoattributename>" +
 " <q1:joinoperator>Inner</q1:joinoperator>" +
 " <q1:linkentities>" +
 " <q1:linkentity>" +
 " <q1:linkfromattributename>systemuserid</q1:linkfromattributename>" +
 " <q1:linkfromentityname>systemuserroles</q1:linkfromentityname>" +
 " <q1:linktoentityname>systemuser</q1:linktoentityname>" +
 " <q1:linktoattributename>systemuserid</q1:linktoattributename>" +
 " <q1:joinoperator>Inner</q1:joinoperator>" +
 " <q1:linkcriteria>" +
 " <q1:filteroperator>And</q1:filteroperator>" +
 " <q1:conditions>" +
 " <q1:condition>" +
 " <q1:attributename>systemuserid</q1:attributename>" +
 " <q1:operator>EqualUserId</q1:operator>" +
 " </q1:condition>" +
 " </q1:conditions>" +
 " </q1:linkcriteria>" +
 " </q1:linkentity>" +
 " </q1:linkentities>" +
 " </q1:linkentity>" +
 " </q1:linkentities>" +
 " </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);

 var resultXml = xmlHttpRequest.responseXML;
 return(resultXml);
}

Function which calls the above function and search for indivisual role:

function UserHasRole(roleName)
{
 //get Current User Roles, oXml is an object
 var oXml = GetCurrentUserRoles();
 if(oXml != null)
 {
  //select the node text
  var roles = oXml.selectNodes("//BusinessEntity/q1:name");
  if(roles != null)
  {
   for( i = 0; i < roles.length; i++)
   {
    if(roles[i].text == roleName)
    {
     //return true if user has this role
     return true;
    }
   }
  }
 }
 //otherwise return false
 return false;                                              
}

How to use UserHasRole function:

if(UserHasRole(“System Administrator”) == true)
{
           alert(‘User has admin role’);
}
else
{
           alert(‘User does not have admin role’);
}