var tips = new Array(3);
var imgAry = new Array(3);
var linkAry = new Array(3);
//var url = "http://www.newsbook.net";

imgAry[0] = "http://ad.newsbook.net/images/newsbook_server.gif";
imgAry[1] = "http://ad.newsbook.net/images/newsbook_banner_s.gif";
imgAry[2] = "http://ad.newsbook.net/images/1161.gif";

linkAry[0] = "http://www.newsbook.net/chi/server-rental-with-colocation.htm";
linkAry[1] = "http://www.newsbook.net/chi/hosting.htm";
linkAry[2] = "http://www.1161.com";

index = Math.floor(Math.random() * tips.length)
var line="<a href="+linkAry[index]+" target=\"_blank\"><img src="+imgAry[index]+" border=0></a>";
document.writeln(line);