"window.location.href"、"location.href"、"parent.location.href"、"top.location.href"

js中"window.location.href"、"location.href"、"parent.location.href"、"top.location.href"的用法
"window.location.href"、"location.href"是本页面跳转
"parent.location.href"是上一层页面跳转
"top.location.href"是最外层的页面跳转
举例说明：
如果A,B,C,D都是jsp，D是C的iframe，C是B的iframe，B是A的iframe，如果D中js这样写
"window.location.href"、"location.href"：D页面跳转
"parent.location.href"：C页面跳转
"top.location.href"：A页面跳转
如果D页面中有form的话,
<form>: form提交后D页面跳转
<form target="_blank">: form提交后弹出新页面
<form target="_parent">: form提交后C页面跳转