var p=4;  
var q=Math.floor(Math.random()*p+1)  
switch(q) 
{ 

case 1: 
document.writeln("<a href=\"http:\/\/www.misslove.org\" target=\"_blank\"><IMG height=76 src=\"\/images\/ad1.gif\" width=445 border=0><\/a>")
break; 

case 2: 
document.writeln("<a href=\"http:\/\/www.sadsnow.cn\" target=\"_blank\"><IMG height=76 src=\"\/images\/wen.gif\" width=445 border=0><\/a>")
break; 

case 3: 
document.writeln("<a href=\"http:\/\/www.puresky.org\" target=\"_blank\"><IMG height=76 src=\"\/images\/ad2.gif\" width=445 border=0><\/a>")
break; 

case 4: 
document.writeln("<a href=\"http:\/\/www.starce.com\" target=\"_blank\"><IMG height=76 src=\"\/images\/yuanfen.gif\" width=445 border=0><\/a>")
break; 
}