jQuery Grid Plugin - jqGrid

When I inline edit a record I do not want to have the required field set. The reason is that they cant change the field via the inline edit. But when they go to add a new record I want the required functionalty to be on.

I have tried using

 beforeCheckValues: function(postdata, formid, mode){
           alert("test")
                },

but for some reason it wont fire off. The record added and the form reloads without showing me a alert box.

Any ideas?