Display modal form before user leaves page

The unload event will fire when a user tries to navigate away. However, if you use a DIV as a pop-up the browser will navigate away before the user has a chance to read it.

To keep them there you'd have to use a alert/prompt/confirm dialog boxes. (as far as I know)

Binding to a html has worked very well for me instead of unload. The reason is well explained in another answer here.

$("html").bind("mouseleave", function () {
    $('#emailSignupModal').modal(); \\or any modal
    $("html").unbind("mouseleave");
});

If you want to show the modal only once in a day or on any other particular condition match then you can use cookies.

Is there a way to do this?

Nope.

You are stuck with the prompt the browser gives you.