Sometimes when the response is slow, one might click the submit button multiple times.
How to prevent this from happening?
Use unobtrusive javascript to disable the submit event on the form after it has already been submitted. Here is an example using jQuery.
EDIT: Fixed issue with submitting a form without clicking the submit button. Thanks, ichiban.
$("body").on("submit", "form", function() {
$(this).submit(function() {
return false;
});
return true;
});