var m=3; //共几个广告随机显示
var n=Math.floor(Math.random()*m+1)
switch(n)
{  
case 1: 
document.writeln("<iframe scrolling=\"no\" width=\"900\" height=\"90\" src=\"http:\/\/code.2bj.cc:8899\/click.html?adid=532&uid=xyl0815\" frameborder=\"0\" marginheight=0 marginwidth=0 ><\/iframe>");
break;
case 2: 
document.writeln("<iframe scrolling=\"no\" width=\"960\" height=\"90\" src=\"http:\/\/code.2bj.cc:8899\/click.html?adid=538&uid=xyl0815\" frameborder=\"0\" marginheight=0 marginwidth=0 ><\/iframe>");
break;
case 3: 
document.writeln("<iframe scrolling=\"no\" width=\"950\" height=\"90\" src=\"http:\/\/code.2bj.cc:8899\/click.html?adid=534&uid=xyl0815\" frameborder=\"0\" marginheight=0 marginwidth=0 ><\/iframe>");
break;
}