listen to the form submission event
$('form').submit(function (e) {
    var form = this;
    e.preventDefault();
    setTimeout(function () {
        form.submit();
    }, 10000); // in milliseconds
    $("<p>thank you for your submittion</p>").appendTo("body");
});
or try this:
$("#submission_button").on("click", function(e) {
    e.preventDefault();//prevent default action 
});
1
solved Adding a ‘Thank You’ popup after I click ‘Submit’ on Bootstrap Modal form? [closed]