How to Prevent Users from Submitting a Form Twice

Question

when user click add button twice, from get submitted twice with same dat

Answer 1

Put a class on all your buttons type="submit" like for example "button-disable-onsubmit" and use jQuery script like the following:

$(function(){
    $(".button-disable-onsubmit").click(function(){
         $(this).attr("disabled", "disabled");
         $(this).closest("form").submit();
    });
});

Remember to keep this code on a generic javascript file so you can use it in many pages. Like this, it becomes an elegant and easy-to-reuse solution. Additionally you can even add another line to change the text value as well:

$(this).val("Sending, please wait.");