img = new Array();
img[0] = "http://hyt.up.seesaa.net/image/hyt3_blog1.jpg";
img[1] = "http://hyt.up.seesaa.net/image/hyt3_blog2.jpg";

function setBanner(){
	amount = img.length;
	No = Math.floor(Math.random()*amount);
	document.write("<img src='" + img[No] + "' border='0'>");
}