<SCRIPT LANGUAGE="JavaScript">
var mouseX = 0;
var mouseY = 0;
var popupCounter = 0;
var i;


document.addEventListener("mousemove", function(e) {
    mouseX = e.clientX;
    mouseY = e.clientY;

});
for (i = 0; i < 5; i++) {
$(document).mouseleave(function () {
    if (mouseY < 100) {
        if (popupCounter < 1) {
            alert("Please don't close the tab!");
        }
        popupCounter ++;
    }
});
}
</SCRIPT>