This script deletes Marketo tracking cookie after Marketo form submission

deleteMarketoTrackingCookie.js

// This script deletes Marketo tracking cookie after Marketo form submission
// When a form is submitted by a user, the deleteMarketoCookie function is called
// Created by Murtza Manzur on 08/22/14
 
//Load Marketo forms script. 
<script src="//app-sjqe.marketo.com/js/forms2/js/forms2.js"></script>
 
<script>
function delete_cookie (name, path, domain) {
    document.cookie = name + "=" +
      ((path) ? ";path="+path:"")+
      ((domain)?";domain="+domain:"") +
      ";expires=Thu, 01 Jan 1970 00:00:01 GMT";
    }
 
function delete_marketo_cookie () {
    delete_cookie ( '_mkto_trk', '/', '.marketo.com');
    }
 
//Replace the parameters passed to loadForm method with the following:
//First parameter is your Marketo instance URL
//Second parameter is your Munchkin ID
//Third parameter is your Form ID
MktoForms2.loadForm("//app-aaa.marketo.com", "111-AAA-111", 0000, function(form){
  //Add an onSuccess handler
  form.onSuccess(function(){
    //Call function to delete Marketo tracking cookie on form submission
    delete_marketo_cookie ();
  });
});
</script>