function random(){

url = new Array(2); 
img = new Array(url.length); 

i = Math.floor(Math.random( ) * url.length);

url[0]="http://www.kakutoh.com/pc/cgi-bin/bc/bcvc.cgi?act=c&id=kakutoh_blog5";
img[0]="http://www.kakutoh.com/pc/cgi-bin/bc/bcvc.cgi?act=n&id=kakutoh_blog5";

url[1]="http://www.kakutoh.com/pc/cgi-bin/bc/bcvc.cgi?act=c&id=kakutoh_blog6";
img[1]="http://www.kakutoh.com/pc/cgi-bin/bc/bcvc.cgi?act=n&id=kakutoh_blog6";


/*これ以降は、3,4,5と数字を増やしてください。*/

document.write('<a href="'+url[i]+'" target="_blank">'); 
document.write('<img src="'+img[i]+'" border="0"></a>');

}