How to disable a submit button after submission in PHP?

Question

I browsed through the other questions on this issue but couldn\'t find a satisfactory answer. I have a quiz website where the user selects an option from four options and then c

Answer 1

For disable write like this, after once click it will be disable.

    $("#but_sub").click(function() {
        $(this).attr("disabled",true);
    }

or

    $('#but_sub').click(function() {
        $(this).attr("disabled","disabled");
    }