How to disable submit button while submitting with addEventListener(submit)?

Question

Everything is said. I spent hour figuring out how to do that simple thing. I can disable this button before the listener (it exists) Here is my code, can you find what is wrong :

 f = document.getElementById(formname)
subBtn = $(f).find(':submit');
f.addEventListener('submit', function (event) {
    subBtn.disabled=true; // Nothing happens
    $(subBtn).prop("disabled",true); // Nothing happens
    $(subBtn).attr("disabled","disabled"); // Nothing happens
    event.preventDefault();
    window["submit_"+formname](f,function(sub){
        if (sub) {
            f.submit();
        } else {
            $(f).find(':submit').attr("disabled", false);
        }
     });
});

I even try with jQuery.submit() instead of addEventListener, same, button is never disabled.