var msg = new Array(); 
msg[0] = '<div class="mb21"><a href="http://www.nileport.com/jump/index.html?id=1357" target="_blank"><img src="http://cn.nileport.com/images/common/300x250peninsula.jpg" width="300" height="250"alt="peninsula" border="0"></a></div>';
msg[1] = '<div class="mb21"><a href="http://www.nileport.com/jump/index.html?id=1356" target="_blank"><img src="http://cn.nileport.com/images/common/300x250zegna.gif" width="300" height="250" alt="Ermenegildo Zegna" border="0"></a></div>';
msg[2] = '<div class="mb21"><a href="http://www.nileport.com/jump/index.html?id=1358" target="_blank"><img src="http://cn.nileport.com/images/common/300x250chaumet.jpg" width="300" height="250" alt="chaumet" border="0"></a></div>';
msg[3] = '<div class="mb21"><a href="http://www.nileport.com/jump/index.html?id=1460" target="_blank"><img src="http://cn.nileport.com/images/common/300x250dfs.jpg" width="300" height="250" alt="DFS环球免税店" border="0"></a></div>';
var no = Math.floor(Math.random() * msg.length); 
document.write(msg[no]);