Javascript to obtain webpage Parameter System

<Script language = "JavaScript">
<! --
Function get_url ()
{
Var src = window. location. href;
Var I = src. substr (src. indexOf ("? U = ") + 3). length;
Var T = src. indexOf ("? U = ");
// Alert (src );
If (0> = T) return "";
If (I = src. length) return-1;
Var url = src. substr (src. indexOf ("? U = ") + 3 );
// Alert (url );
Return url;
}

Function go (url ){
// Alert (url );
Document. write ('Document. write ('Document. write ('<title> www.jb51.net-' + url + '</title> ');
Document. write ('<meta http-equiv = "Content-Type" content = "text/html; charset = gb2312"> ');
Document. write ('
Document. write ('<frameset rows = "30, *" frameborder = "NO" border = "0" frameborder = "0" framespacing = "0"> ');
Document. write ('<frame scrolling = "NO" noresize src = "http://img.jb51.net/api/tuijie/tuijie.htm? U = '+ url +' "> ');
Document. write ('<frame name = "www.jb51.net" src = "' + url + '"> ');
Document. write ('</frameset> ');
Document. write ('}

Go (get_url ());

// -->
Self. status = "jb51.net ";
</SCRIPT>