$("#backPrev").attr("href","javascript:void(0);").click(function(){
if (/(iPhone|iPad|iPod)/i.test(navigator.userAgent)) {
window.location.href = window.document.referrer;
} else { window.history.go("-1"); }
});
参考博文：http://www.cnblogs.com/qingliuyu/archive/2012/05/03/2481305.html