单击并验证后禁用输入

I'm trying to disable an input in a form, but only after validation of fields.

function valJomclAddForm() {
    f = document.jomclForm;
    document.formvalidator.setHandler('list', function (value) {            
        return (value != -1);
    });     
    if (document.formvalidator.isValid(f)) {

        if(document.getElementById('membership6') === null) {
            return false;
        }           
        jQuery('input#submit').val('Publishing...');
        jQuery('input#submit').prop('disabled', true);
        return true;

    } else {
        //alert
    }
}

but when function gets here:

jQuery('input#submit').prop('disabled', true);
return true;

Function stops, change input value to "Publishing" but doesn't publish, doesn't get the "return true"

Unless I remove jQuery('input#submit').prop('disabled', true);then function return true and publish this...

Why does this not work?

Thanks a lot in advance!