功能很简单，代码也很简洁，这里就不多废话了
function fullScreen() {
var el = document.documentElement,
rfs = el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullScreen,
wscript;
if(typeof rfs != "undefined" && rfs) {
rfs.call(el);
return;
}
if(typeof w
