鼠标事件

if ( event.pageX == null && original.clientX != null ) {
     eventDoc = event.target.ownerDocument || document;
     doc = eventDoc.documentElement;
     body = eventDoc.body;
     event.pageX = original.clientX + ( doc && doc.scrollLeft || body && body.scrollLeft || 0 ) - ( doc && doc.clientLeft||body&&body.clientLeft || 0 );
     event.pageY = original.clientY + ( doc && doc.scrollTop  || body && body.scrollTop  || 0 ) - ( doc && doc.clientTop  || body && body.clientTop  || 0 );
 }