function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		topnavroll_04_over = newImage("images/topnavroll_04-over.jpg");
		topnavroll_05_over = newImage("images/topnavroll_05-over.jpg");
		topnavroll_06_over = newImage("images/topnavroll_06-over.jpg");
		topnavroll_07_over = newImage("images/topnavroll_07-over.jpg");
		topnavroll_08_over = newImage("images/topnavroll_08-over.jpg");
		topnavroll_09_over = newImage("images/topnavroll_09-over.jpg");
		topnavroll_10_over = newImage("images/topnavroll_10-over.jpg");
		topnavroll_11_over = newImage("images/topnavroll_11-over.jpg");
		preloadFlag = true;
	}
}


function switch_layer1(id)
{
    var maincell = document.getElementById("main1");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}


function switch_layer2(id)
{
    var maincell = document.getElementById("main2");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";


}
function switch_layer3(id)
{
    var maincell = document.getElementById("main3");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer4(id)
{
    var maincell = document.getElementById("main4");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer5(id)
{
    var maincell = document.getElementById("main5");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer6(id)
{
    var maincell = document.getElementById("main6");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer7(id)
{
    var maincell = document.getElementById("main7");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer8(id)
{
    var maincell = document.getElementById("main8");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer9(id)
{
    var maincell = document.getElementById("main9");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer10(id)
{
    var maincell = document.getElementById("main10");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer11(id)
{
    var maincell = document.getElementById("main11");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}
function switch_layer12(id)
{
    var maincell = document.getElementById("main12");
    var layerlist = maincell.getElementsByTagName("div");

    var i = 0;
    for (i = 0; i < layerlist.length; i++)
    {
        layerlist[i].className = "clayer_hidden";
    }

    document.getElementById(id).className = "clayer_shown";

}