onLoad Catalog Client Script - Populate Variables

I'm trying to write an OnLoad Client Script for a catalog item. On the form we have two reference fields to the sys_user table. One is called Requestor (u_requestor) and the other is On Behalf Of (mrb_on_behalf_of) - this field can be used if someone needs to request access for someone else. 

If this field is populated I want it to populate some fields with that users details (mrb_on_behalf_of), if that field is not filled in then I want it to populate the fields with the Requestors user details (u_requestor). I've got the below script, however it's only working for the Requestors details and not the On Behalf Of. The reason I am using on load is because we're using an order guide and the same variables are on the catalog items.

function onLoad(control, oldValue, newValue, isLoading) {
if (isLoading || newValue == '') {
return;

}
var name = g_form.getReference('mrb_on_behalf_of');
if (name ==null){
userObject = g_form.getReference('u_requestor',setUserInfo);}
else {
userObject = g_form.getReference('mrb_on_behalf_of',setUserInfo);}

function setUserInfo(userObject){
g_form.setValue('division',userObject.u_division);
g_form.setValue('position_title_02',userObject.title);
g_form.setValue('department',userObject.department);

}

}

Thanks in advance