var imagenumber = 3 ;
var randomnumber = Math.random() ;
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1 ;
images = new Array
images[1] = "file/pic/logo/logo1.png"
images[2] = "file/pic/logo/logo2.png"
images[3] = "file/pic/logo/logo3.png"
var image = images[rand1] ;
var linknumber = 3 ;
var img1 = Math.round( (linknumber-1) * randomnumber) + 1 ;
links = new Array
links[1] = "http://www.pet-book.com"
links[2] = "http://www.pet-book.com"
links[3] = "http://www.pet-book.com"
var link = links[img1];
document.write('<a href="' + link + '"><img src="' + image + '" border="0"></a>') ;