var primarySponsorTicks = 0;
var primarySponsorMode = 0;

var secondarySponsorTicks = 0;
var secondarySponsorMode = 0;

var fadeSteps = [ 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100];
var sponsorImagesLoaded = false;

function preloadSponsorImages() {
	if (!sponsorImagesLoaded) {
		sponsorImagesLoaded = true;

		document.getElementById("primarySponsorLnk").href = primarySponsorLinks[primarySponsorMode];
		document.getElementById("primarySponsorImg").alt = primarySponsorAlts[primarySponsorMode];
		document.getElementById("primarySponsorImg").src = primarySponsorImages[primarySponsorMode];

		document.getElementById("secondarySponsorLnk").href = secondarySponsorLinks[secondarySponsorMode];
		document.getElementById("secondarySponsorImg").alt = secondarySponsorAlts[secondarySponsorMode];
		document.getElementById("secondarySponsorImg").src = secondarySponsorImages[secondarySponsorMode];

		primarySponsorMode++;
		secondarySponsorMode++;

		for (var i = 0; i < primarySponsorImages.length; i++) {
			var image1 = new Image();
			image1.src = primarySponsorImages[i];
		}

		for (var i = 0; i < secondarySponsorImages.length; i++) {
			var image1 = new Image();
			image1.src = secondarySponsorImages[i];
		}
	}
}

function swapSponsorImages() {

	preloadSponsorImages();

    if (document &&
        document.getElementById)
    {
		primarySponsorTicks++;
        secondarySponsorTicks++;
		
        if (primarySponsorTicks > -1 &&
            primarySponsorTicks < 21)
        {
            document.getElementById("primarySponsorImg").style.opacity = fadeSteps[primarySponsorTicks] / 100;
            document.getElementById("primarySponsorImg").style.filter = "alpha(opacity=" + fadeSteps[primarySponsorTicks] + ")";
        }
        else if (primarySponsorTicks > 78 &&
            primarySponsorTicks < 100)
        {
            document.getElementById("primarySponsorImg").style.opacity = fadeSteps[100 - primarySponsorTicks] / 100;
            document.getElementById("primarySponsorImg").style.filter = "alpha(opacity=" + fadeSteps[100 - primarySponsorTicks] + ")";
        }
        else if (primarySponsorTicks >= 100)
		{
            document.getElementById("primarySponsorLnk").href = primarySponsorLinks[primarySponsorMode];
			document.getElementById("primarySponsorImg").alt = primarySponsorAlts[primarySponsorMode];
            document.getElementById("primarySponsorImg").src = primarySponsorImages[primarySponsorMode];

            primarySponsorTicks = 0;
            primarySponsorMode++;

            if (primarySponsorMode >= primarySponsorImages.length) 
            {
                primarySponsorMode = 0;
            }
		}

        if (secondarySponsorTicks > -1 &&
            secondarySponsorTicks < 21)
        {
            document.getElementById("secondarySponsorImg").style.opacity = fadeSteps[secondarySponsorTicks] / 100;
            document.getElementById("secondarySponsorImg").style.filter = "alpha(opacity=" + fadeSteps[secondarySponsorTicks] + ")";
        }
        else if (secondarySponsorTicks > 78 &&
            secondarySponsorTicks < 100)
        {
            document.getElementById("secondarySponsorImg").style.opacity = fadeSteps[100 - secondarySponsorTicks] / 100;
            document.getElementById("secondarySponsorImg").style.filter = "alpha(opacity=" + fadeSteps[100 - secondarySponsorTicks] + ")";
        }
        else if (secondarySponsorTicks >= 100)
		{
			document.getElementById("secondarySponsorLnk").href = secondarySponsorLinks[secondarySponsorMode];
			document.getElementById("secondarySponsorImg").alt = secondarySponsorAlts[secondarySponsorMode];
            document.getElementById("secondarySponsorImg").src = secondarySponsorImages[secondarySponsorMode];

            secondarySponsorTicks = 0;
            secondarySponsorMode++;

            if (secondarySponsorMode >= secondarySponsorImages.length) 
            {
                secondarySponsorMode = 0;
            }
		}

        setTimeout("swapSponsorImages()", 50);
    }
}

window.onload = swapSponsorImages;