Javascript - Stop form submit depending on ajax response [duplicate]

Answer 1

use e.preventDefault(); to prevent the form from submitting, and then use this.submit() (isn't calling the jQuery .submit() trigger function, but rather the native

.submit() function) to submit the form.

$("form").submit(function(e) {
            e.preventDefault();
            var tray = $('select[name=tray_id]').val();
            var form = this;
            $.ajax({
                type: "POST",
                url: "modules/reserve-check.php",
                data: {tray_id: tray},
                cache: false,
                complete : function(result){callback(result, form)}
            });       
        });

var callback = function(result, form){
  if(!result)
    form.submit();
};