表单禁止二次提交

gistfile1.txt

$("form").submit(function() {
        $(this).submit(function() {
            return false;
        });
        return true;
    });


$( "#target" ).submit(function( event ) {
  alert( "Handler for .submit() called." );
  event.preventDefault();
});
Now when the form is submitted, the message is alerted. 
This happens prior to the actual submission, so we can cancel 
the submit action by calling .preventDefault() on the event 
object or by returning false from our handler. 
We can trigger the event manually when another element is clicked:
该回调函数会在提交表单前运行，禁用默认方法或者返回false可以禁止提交

ref: https://api.jquery.com/submit/