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(24)); //改成你要随机显示的图片数；
    if(myNum == 1) document.write("<img src='../images_en/1.jpg'>"); 
if(myNum == 2) document.write("<img src='../images_en/2.jpg'>"); //图片路径，可用http://
if(myNum == 3) document.write("<img src='../images_en/3.jpg'>"); 
if(myNum == 4) document.write("<img src='../images_en/01.jpg'>"); 
if(myNum == 5) document.write("<img src='../images_en/02.jpg'>"); 
if(myNum == 6) document.write("<img src='../images_en/03.jpg'>");  
if(myNum == 7) document.write("<img src='../images_en/05.jpg'>"); 
if(myNum == 8) document.write("<img src='../images_en/06.jpg'>"); 
if(myNum == 9) document.write("<img src='../images_en/07.jpg'>"); 
if(myNum == 10) document.write("<img src='../images_en/08.jpg'>"); 
if(myNum == 11) document.write("<img src='../images_en/09.jpg'>"); 
if(myNum == 12) document.write("<img src='../images_en/10.jpg'>");  
if(myNum == 13) document.write("<img src='../images_en/11.jpg'>");  
if(myNum == 14) document.write("<img src='../images_en/12.jpg'>");  
if(myNum == 15) document.write("<img src='../images_en/13.jpg'>"); 
if(myNum == 16) document.write("<img src='../images_en/14.jpg'>"); 
if(myNum == 17) document.write("<img src='../images_en/15.jpg'>"); 
if(myNum == 18) document.write("<img src='../images_en/16.jpg'>"); 
if(myNum == 19) document.write("<img src='../images_en/17.jpg'>"); 
if(myNum == 20) document.write("<img src='../images_en/18.jpg'>"); 
if(myNum == 21) document.write("<img src='../images_en/19.jpg'>"); 
if(myNum == 22) document.write("<img src='../images_en/20.jpg'>"); 
if(myNum == 23) document.write("<img src='../images_en/21.jpg'>"); 
if(myNum == 24) document.write("<img src='../images_en/22.jpg'>"); 
    else {
document.write();
}

};

document.write("</CENTER>");