兼容的event获取目标

document.getElementById('clickTest').onclick = function(event){
    var event = event? event: window.event
    var obj = event.srcElement ? event.srcElement:event.target; 
    //obj.closest('.'+notClose[i]).length > 0 || obj.parents().closest('.'+notClose[i]).length > 0
    alert(obj.id);
}