Invite all friends to event

javascript:var x=document.getElementsByTagName("input");for(var i=0;i<x.length;i++) {if (x[i].type == 'checkbox') {x[i].click();}}; alert('Done, all your friends have been selected');

In order to use this code, copy and paste it in the address bar of your browser after you have opened the “invite your friends” dialog and AFTER YOU HAVE SCROLLED DOWN THE LIST.
Important

 note: as said, you HAVE to scroll down your friends list in order to invite all your friends: in fact the new interface only loads via AJAX some friends at a time.