2. Example: Create 4 html files
The first html file index01
<html> <head></head> <iframe scr="framec.html" width="800px" heigth="800px"></iframe> </html>
The second html file framea.html
<body bgcolor="blue"></body> <a href="baidu.com" target="1">百度</a>
The third html file frameb.html
<body bgcolor="red"> <iframe scr="framea.html" width="600px" heigth="600px"></iframe> </body>
The fourth html file framec.html
<body bgcolor="green"> <iframe scr="frameb.html" width="400px" heigth="400px"></iframe> </body>
At this point, a three-fold nested page is generated.
When the value of self is _self, the link is opened on page a.
When the value of self is _blank, it is opened on a new page.
When the value of self is _parent, the link is opened on the parent page. Open in the top-level page
when the value of self is _top