Execute javascript code straight before page submit

Question

There are a few similar questions to this but none quite the same.

I want to know if there is an event that can be used to execute some JS before a page is submitting (i.e. POSTed).

Answer 1

Something like this?

<form onsubmit="do_something()">  function do_something(){    // Do your stuff here } 

If you put return like the code below, you can prevent the form submission by returning false from the do_something() function.

<form onsubmit="return do_something()">  function do_something(){    // Do your stuff here    return true; // submit the form     return false; // don't submit the form }