Enabled and disable fields based on a user role

All had a question to see if this could be done and this is the code that was used to enabled and disable fields based on a user role when a value is changed in a list box change event.

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;
}

function GetCurrentUserRoles()
{
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>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);
}


//This is the code used to enable or disable the fields in CRM 4.

try
{
if(crmForm.all.isp_goodwill.DataValue == '1') //List box selected = yes
{
if(UserHasRole("Goodwill Manager")) //Role to look for
{
//Fields to enable.
crmForm.all.isp_goodwillrequestedbyid.Disabled = false;
crmForm.all.isp_goodwillapprovedbyid.Disabled = false;
crmForm.all.isp_goodwillvalueapproved.Disabled = false;
}
}
}
catch(e)
{
alert(this.gErrorMessage("Authorisation Form",e.description ));
}