Check if g_user is a memger of an assignment group

[#1]

I need to be able to check if a current user is a member of the assignment group from a client script. I created a (global) business rule:

function CheckIfUserMemberOf(usr, assign_gr){
var grm = new GlideRecord('sys_user_grmember');
grm.addQuery ('user', usr);
grm.addQuery ('group', assign_gr);
grm.query();

if (grm.next()) {
return true;
}
else {
return false;
}
}

and a client script to run it:

function onLoad() {

var usr = g_user.userName;
var assign_gr = g_form.getValue('assignment_group');

var script = "CheckIfUserMemberOf('" + usr + "','" + assign_gr + "')";
var answer = AJAXEvaluateSynchronously(script);
alert(answer);
}

but I'm always getting a false alert, as if the query was wrong. Can anybody help?

[Mark Stanger]

Try changing this line...
var usr = g_user.userName;

to this...
var usr = g_user.userID;

[#3]

It works. Cheers!