(function($) {
 
var types = ['DOMMouseScroll', 'mousewheel'];
 
$.event.special.mousewheel = {
setup: function() {
if ( this.addEventListener )
for ( var i=types.length; i; )
this.addEventListener( types[--i], handler, false );
else
this.onmousewheel = handler;
},
 
teardown: function() {
if ( this.removeEventListener )
for ( var i=types.length; i; )
this.removeEventListener( types[--i], handler, false );
else
this.onmousewheel = null;
}
};
 
$.fn.extend({
mousewheel: function(fn) {
return fn ? this.bind("mousewheel", fn) : this.trigger("mousewheel");
},
 
unmousewheel: function(fn) {
return this.unbind("mousewheel", fn);
}
});
 
 
function handler(event) {
var args = [].slice.call( arguments, 1 ), delta = 0, returnValue = true;
 
event = $.event.fix(event || window.event);
event.type = "mousewheel";
 
if ( event.wheelDelta ) delta = event.wheelDelta/120;
if ( event.detail ) delta = -event.detail/3;
 
// Add events and delta to the front of the arguments
args.unshift(event, delta);
 
return $.event.handle.apply(this, args);
}
 
})(jQuery);