img = new Array();
img[0] = "images/photo_intoro01.png";
img[1] = "images/photo_intoro02.png";
img[2] = "images/photo_intoro03.png";
img[3] = "images/photo_intoro04.png";

function setBanner(){
	amount = img.length;
	No = Math.floor(Math.random()*amount);
	document.write("<img src='" + img[No] + "'  class='alphafilter mgt5'>");
}