Prevent Default on Form Submit jQuery

Use the new "on" event syntax.

$(document).ready(function() {
  $('form').on('submit', function(e){
    // validation code here
    if(!valid) {
      e.preventDefault();
    }
  });
});

Cite: https://api.jquery.com/on/

This is an ancient question, but the accepted answer here doesn't really get to the root of the problem.

You can solve this two ways. First with jQuery:

$(document).ready( function() { // Wait until document is fully parsed
  $("#cpa-form").on('submit', function(e){

     e.preventDefault();

  });
})

Or without jQuery:

// Gets a reference to the form element
var form = document.getElementById('cpa-form');

// Adds a listener for the "submit" event.
form.addEventListener('submit', function(e) {

  e.preventDefault();

});

You don't need to use return false to solve this problem.

Try this:

$("#cpa-form").submit(function(e){
    return false;
});