JAVASCRIPT

add parameter to serialize javascript

var data = $(this).serializeArray(); // convert form to array
data.push({name: "NonFormValue", value: NonFormValue});
$.ajax({
    type: 'POST',
    url: this.action,
    data: $.param(data),
});

add parameter to serialize javascript

 data: $(this).serialize() + '&=NonFormValue' + NonFormValue,