Call function when user wants to leave the website

callWhenLeaves.js

(function(g,e,c){if(typeof g!="function"){return}var d=false;var f=0;var b=function(){var h=(new Date).getTime();if(d&&(f==0||e&&h-f>c)){document.removeEventListener("mouseleave",b);f=h;g()}};var a=function(j){var h=innerHeight/10;var i=j.movementY;var k=j.clientY;if(i<0&&k<h){d=true;document.addEventListener("mouseleave",b)}else{document.removeEventListener("mouseleave",b);d=false}};document.addEventListener("mousemove",a)})(
    function () { // callback function
        alert("Do not leave!")
    },
    true, // repeat calling
    5000  // interval in milliseconds
);