I encountered this error while I was trying to create a dynamic web page. I am really new at PHP AJAX JS MySQL json. The error occurs at specifically at line with Grade': $('#Grade').val()
$('form').submit(function(event) {
$('#std_id + .throw_error').empty();
$('#std_name + .throw_error').empty();
$('#Grade + .throw_error').empty();
$('#Age + .throw_error').empty();
$('#Phone + .throw_error').empty();
$('#success').empty();
var postForm ={
'std_id': $('#std_id').val(),
'std_name': $('#std_name').val()
'Grade': $('#Grade').val(),
'Age': $('#Age').val()
'Phone': $('#Phone').val()
};