function handle(delta) {
if (delta < 0)
…;
else
…;
}
/** Event handle
*/
function wheel(event){
var delta = 0;
if (!event) /* For IE. */
event = ;
if () { /* IE or Opera. */
delta = /120;
/** In Opera9, event handling is different from IE
*/
if ()
delta = -delta;
} else if () { /** Compatible with Mozilla. */
/** In Mozilla, sign of delta is different than in IE.
* Also, delta is multiple of 3.
*/
delta = -/3;
}
/** If the increment is not equal to 0, it will be triggered
* The main function is to test the roller roll upward or downward
*/
if (delta)
handle(delta);
}
/** Initialization */
if ()
/** Mozilla's DOM-based scroll wheel event **/
('DOMMouseScroll', wheel, false);
/** IE/Opera. */
= = wheel;