var set = 16;     
	var pic = new Array(set);  
        
	pic[0] = "images/header_18.jpg";
	pic[1] = "images/header_1.jpg";
	pic[2] = "images/header_2.jpg";
	pic[3] = "images/header_3.jpg";
	pic[4] = "images/header_5.jpg";
	pic[5] = "images/header_6.jpg";
	pic[6] = "images/header_7.jpg";
	pic[7] = "images/header_8.jpg";
	pic[8] = "images/header_9.jpg";
	pic[9] = "images/header_10.jpg";
	pic[10] = "images/header_11.jpg";
	pic[11] = "images/header_13.jpg";
	pic[12] = "images/header_14.jpg";
	pic[13] = "images/header_15.jpg";
	pic[14] = "images/header_16.jpg";
	pic[15] = "images/header_17.jpg";

	function select(range) {
	if (Math.random)
	return Math.round(Math.random() * (range-1));
	else {
	var now = new Date();
	return (now.getTime() / 1000) % range;
	} }

	var choice = select(set);