function random_imglink(){

var myimages=new Array()

myimages[1]="http://ws2.y-bbs.net/k/koukoku.gif"

var imagelinks=new Array()

imagelinks[1]="http://y-bbs.net/koukoku.html"

var ry=Math.floor(Math.random()*myimages.length)

if (ry==0)

ry=1

document.write('<a href='+'"'+imagelinks[ry]+'"'+' target="_blank"><img src="'+myimages[ry]+'" border=0></a>')
}
random_imglink()