var rnd = (Math.random().toString()).substring(2);
var NS4 = (document.layers) ? true : false;
var imgs = new Array();
var banners = new Array();
var img_ctr = 0;
var global_img_ctr = 0;
var debug = 0;

function banner_details(page_id, height, width, primary, backup)
{
    this.page_id = page_id;
    this.height = height;
    this.width = width;
    this.primary = primary;
    this.backup = backup;
}

function create_banner_code(ctr, page_id, height, width)
{
    create_banner(page_id, height, width);
}

function create_banner(page_id, height, width)
{
    var primary = "http://banner-feed.digitallook.com";
    var backup = "http://banner-feed2.digitallook.com";

    create_pallette(page_id);

    global_img_ctr++;

    var ctr = global_img_ctr;

    img_ctr = ctr;

    imgs[img_ctr] = new Image();
    banners[img_ctr] = new banner_details(page_id, height, width, primary, backup);

	imgs[img_ctr].onload = function (){loadHandler(ctr);};
	imgs[img_ctr].onerror = function (){errorHandler(ctr);};
	imgs[img_ctr].src = primary + '/blank.gif?' + rnd;
}

function errorHandler (ctr) 
{
    img_ctr = ctr;
	if (imgs[img_ctr].src.indexOf(banners[img_ctr].primary) != -1)
    	imgs[img_ctr].src = banners[img_ctr].backup + '/blank.gif?' + rnd;
}

function create_pallette(page_id)
{
    if (debug) alert("drawing pallette for " + page_id);

	if (NS4)
	{
        // do nothing
    }
	else
	    document.writeln('&nbsp;<span id="frame' + page_id + '"></span>');
}


function draw_code(src_html, page_id)
{
    if (NS4)
    {
        // do nothing
    }
    else
    {
        if (document.getElementById)
            document.getElementById("frame" + page_id).innerHTML=src_html; // check
        else if (document.all) 
        {
            var usable_frame = eval("frame" + page_id);
        	usable_frame.innerHTML=src_html;
        }
    }

}

function loadHandler (ctr)
{

    var page_id, width, height;

    img_ctr = ctr;

    page_id = banners[img_ctr].page_id;
    width = banners[img_ctr].width;
    height = banners[img_ctr].height;

    if (imgs[img_ctr].src.indexOf(banners[img_ctr].primary) != -1)
    {
        var s1='<iframe width=' + width + ' height=' + height + ' src="' + banners[img_ctr].primary + '/window/?page_id=' + page_id + '&rnd=' + rnd + '" marginheight=0 marginwidth=0 border=0 frameborder=0 scrolling=no name=ifmainnav></iframe>';
        s1+='  <layer width=' + width + 'px height=' + height + 'px src="' + banners[img_ctr].primary + '/window/?page_id=' + page_id + '&rnd=' + rnd + '"></layer>';

        if (debug) alert(page_id + ": drawing primary");

    	draw_code(s1, page_id);
    }
    else if (imgs[img_ctr].src.indexOf(banners[img_ctr].backup) != -1)
    {
        var s1 = '<iframe width=' + width + ' height=' + height + ' src="' + banners[img_ctr].backup + '/window/?page_id=' + page_id + '&rnd=' + rnd + '" marginheight=0 marginwidth=0 border=0 frameborder=0 scrolling=no name=ifmainnav></iframe>';
        s1 += ' <layer width=' + width + 'px height=' + height + 'px src="' + banners[img_ctr].backup + '/window/?page_id=' + page_id + '&rnd=' + rnd + '"></layer>';

        if (debug) alert(page_id + ": drawing backup");

        draw_code(s1, page_id);
    }
    // else we don't display anything
}