jumpURL = new Array();
imgURL  = new Array();
jumpURL[0] = "http://www.union-g.com/products/list.php?category_id=26";
imgURL[0]  = "/user_data/packages/default/img/top.jpg";

n = Math.floor(Math.random()*jumpURL.length);
document.write("<a href='"+jumpURL[n]+"'>"); 
document.write("<img src='"+imgURL[n]+"' border='0' >");
document.write("</a>");