window.location.href,window.location.replace区别。
window.location.href("./a.htm");//执行后有后退、前进
window.location.replace("./a.htm");//执行后无后退、前
top.location.href="/url" 顶层页面打开url
self.location.href="/url"本页面打开url地址
parent.location.href="/url" 父窗口打开Url地址
this.location.href="/url" 用法和self的用法一致,当前窗口打开