var num_of_banner_tren = 2;

Banner_of_tren = new Array(num_of_banner_tren);
Banner_of_tren[0] = '<img src="img_title/stan-d-art_it_poster_001_ay.jpg" title="www.stan-d-art.spb.ru" width="764" height="260" hspace="0" vspace="0" border="0">';
Banner_of_tren[1] = '<img src="img_title/stan-d-art_it_poster_001_ay.jpg" title="www.stan-d-art.spb.ru" width="764" height="260" hspace="0" vspace="0" border="0">';

function getrandom() {
	var min_random = 0;
	var max_random = num_of_banner_tren-1;
	max_random++;
	var range = max_random - min_random;
	var n=Math.floor(Math.random()*range) + min_random;
	return n;
}

var i, j;
var flag; 
var banners_show = 1;
var rand = new Array(banners_show-1);
for (i=0; i<banners_show; i++) {
    do {
        flag=0;
        n = getrandom();
        for (j=0; j<i; j++) {
            if (n == rand[j]) {
                flag=1;
            }
        }
    } while (flag);
    rand[i] = n;
}

function show_banner_tren(){
document.write(Banner_of_tren[rand[0]]);
}