Confirm form field change before saving

confirm-change.js

var needToConfirm = false;

$("input,textarea").on("input", null, null, function() {
    needToConfirm = true;
});

$("select").change(function() {
    needToConfirm = true;
});

window.onbeforeunload = function(){
    if(needToConfirm) {
        return "If you exit this page, your unsaved changes will be lost.";        
    }
};