Event.observe(window, 'load', randombanner, false);

function randombanner () {
imgList = new Array()

imgList = [
			["img/img_banner01.jpg","http://solarquest.rcast.u-tokyo.ac.jp/en/"],
			["img/img_banner02.png","rcast/director/"],
			["img/img_banner03.jpg","research/ais/index.html"]
		]
var n = Math.floor(Math.random() * imgList.length);

var con = $('bannerArea');

var contentsData = "";

for (i=0; i<imgList.length; i++) {
	if(i==0){
		contentsData += "<ul>"
	}
	if(i != n){
		contentsData += "<li>"
		contentsData += imgList[i][1]?"<a href='" + imgList[i][1] + "'>":""
		contentsData += "<img src='" + imgList[i][0] + "' alt='' width='336' height='110' />"
		contentsData += imgList[i][1]?"</a>":""
		contentsData += "</li>"
	}
	if(i==imgList.length){
		contentsData += "</ul>"
	}
}
	con.innerHTML = contentsData;

}