var randomMsg = Math.floor(Math.random() * 5);
if(randomMsg == 0) document.write('<img src="images/top/banner_05a.jpg" width="145" height="100" />');
else if(randomMsg == 1) document.write('<img src="images/top/banner_05a.jpg" width="145" height="100" />');
else if(randomMsg == 2) document.write('<img src="images/top/banner_05c.jpg" width="145" height="100" />');
else if(randomMsg == 3) document.write('<img src="images/top/banner_05c.jpg" width="145" height="100" />');
else if(randomMsg == 4) document.write('<img src="images/top/banner_05c.jpg" width="145" height="100" />');