JS兼容性总结

obj.currentStyle ? obj.currentStyle[attr] : getComputedStyle(obj)[attr];   =>currentStyle为IE

var scroll = document.documentElement.scrollTop || document.body.scrollTop =>body为chrome

var ev = ev || event;  event为IE和chrome，ev为标准

obj.attachEvent(‘onclick‘,fn);  IE
obj.addEventListener(‘click‘,fn,false);标准

obj.detachEvent(‘onclick‘,fn);  IE
obj.removeEventListener(‘click‘,fn,false) 标准