js原生函数检查浏览器支持的css3属性前缀

supportTransition = (function () {
var s = document.createElement('p').style,
r = 'transition' in s ||
'WebkitTransition' in s ||
'MozTransition' in s ||
'msTransition' in s ||
'OTransition' in s;
s = null;
return r;
})()