You would need an if statement more like this:
if (g_form.getValue('request_type') == 'Group Create') {
The variable named request_type can exist within or outside of the variable set in this case. You would also want to confirm that 'Group Create' is the value stored in that variable - if it's a select box you could have that has a choice label, but a different value. MRVS onSubmit scripts are triggered when the Add button is clicked (the second time, inside the Add Row dialog window) and can interact with the parent form (other Catalog Item variables).
