阻止事件的传播兼容
function(e){
var e=e||window.event;
e.stopPropagation();
if (e.stopPropagation) {
e.stopPropagation();
}
else{
e.cancelBubble=
true;
}
}
防止事件冒泡
function stopBubble(e) {
if(e && e.stopPropagation) {
e.stopPropagation();
}
else {
window.event.cancelBubble =
true;
}
}