var buttons = document.getElementsByClassName('form-submit-button');
buttons[0].addEventListener('click', function(){
   executeTracking();
   submitForm();
}

var submitForm = function(self) {
    // alert('form')
    self.parentNode.getElementsByTagName('form')[0].submit();
}
var fireTracking = function(cta, self, callback) {
    // alert('mixpanel')
    tracking.track();
    callback(self);
}
var buttons = document.getElementsByClassName('form-submit-button');
buttons[0].addEventListener('click', function(){
    fireTracking(cta, this, submitForm);
}, true);