I just want to test it to show a simple alert if it works. But I can't make it work. what is the problem here? Please help me guys

jQuery("#grid_grades_subjects").jqGrid('navGrid','#nav_grades_subjects',{edit:true,add:true,del:true}{

afterSubmit: function(response, postdata){

alert("testing");

return [false, "testing message", null];

}

});