Close the browser window pop-up prompt box and control its invalidation_javascript skills

Run the following code when the js page is loading

Copy the code The code is as follows:

window.onbeforeunload = function(){
return "Unsaved content may be lost";

};

This code will not display the return value in Firefox and IE in Google This text is displayed under the browser.

Failure control

triggers js to run as follows:

Copy code The code is as follows:

window.onbeforeunload = function(){};