<!--  
today=new Date();  
jran=today.getTime();  

function rnd() {  

    ia=9301;  
    ic=49297;  
    im=233280;  

    jran = (jran*ia+ic) % im;  
    return jran/(im*1.0);  
};  

function rand(number) {  

    return Math.ceil(rnd()*number);  
};  

document.write("<CENTER>");  
for(i=1;i<=1;i++) {  
    myNum=(rand(3)); //改成你要随机显示的图片数；  
    if(myNum == 1) document.writeln("<a href=\"http://xuewei.chinazikao.com/junzikao/\" target=\"_blank\"><img src=\"http://www.chinazikao.com/images/2010junzikao1.jpg\" alt=\"1.5年自考本科\"  border=\"0\"/></a> ");
if(myNum == 2) document.writeln("<a href=\"http://xuewei.chinazikao.com/junzikao/\" target=\"_blank\"><img src=\"http://www.chinazikao.com/images/2010junzikao2.jpg\" alt=\"1.5年自考本科\"  border=\"0\"/></a> "); //图片路径，可用http://  
if(myNum == 3) document.writeln("<a href=\"http://xuewei.chinazikao.com/junzikao/\" target=\"_blank\"><img src=\"http://www.chinazikao.com/images/2010junzikao.jpg\" alt=\"1.5年自考本科\"  border=\"0\"/></a> ");  
    else {  
document.write();  
}  

};  

document.write("</CENTER>");  
//-->