CORE-562 Script error when saving a response

This method "bindXHRToButton_disable" is exactly same as "bindXHRToButton", but after the ajax is returned we are adding disable class to the buttons, which is the original state when the modal starts. This is triggered only when "Save&Add Another" button is clicked.  So the user can add name, description etc and after all required fields, the form is validated and buttons are enabled. 
We are adding disabled class, because I think we are trying to prevent second click incase the ajax takes too long.