For data that can change during the user experience, replace g_form.getReference with GlideAjax, a callback function, and a custom function in a Script Include that returns only the needed information. For data that remains the same after the form loads and can be determined before the form loads, replace g_form.getReference with a Display Business Rule and g_scratchpad. If using getXMLWait, replace with getXML and a callback function.