dom js

           var addEvent = function( obj, type, fn ) {
                if (obj.addEventListener)
                    obj.addEventListener( type, fn, false );
                else if (obj.attachEvent) {
                    obj["e"+type+fn] = fn;
                    obj.attachEvent( "on"+type, function() {
                        obj["e"+type+fn]();
                    });
                }
            };