Here in stackoverflow, if you started to make changes then you attempt to navigate away from the page, a javascript confirm button shows up and asks: \"Are you sure you want
This is an easy way to present the message if any data is input into the form, and not to show the message if the form is submitted:
$(function () {
$("input, textarea, select").on("input change", function() {
window.onbeforeunload = window.onbeforeunload || function (e) {
return "You have unsaved changes. Do you want to leave this page and lose your changes?";
};
});
$("form").on("submit", function() {
window.onbeforeunload = null;
});
})