Delete cookies on page refresh

Question

How do I delete cookies via JavaScript when you refresh a page ? I wanted to do this using the event onbeforeunload.

Answer 1

Why you want to remove a cookie before it has a chance to be sent back to the server is beyond me, but here you go:

window.onbeforeunload = function(e) {
    document.cookie = 'cookiename=; expires=' + d.toGMTString() + ';';
};