IE4 = (document.all) ? 1 : 0;
NS4 = (document.layers) ? 1 : 0;
i = 1;
lastPage = 18;

function first()
        {
                showLayer("Bild1");
                hideLayer("Bild" + i);
                //alert("Bild1");
        }

function next()
{
        if (i < lastPage)
        {
                i++;
                showLayer("Bild" + i);
                hideLayer("Bild" + (i-1));
                //alert("Bild" + i);
        }
        else
        {
                i=1;
                showLayer("Bild" + i);
                hideLayer("Bild" + lastPage);
                //alert("Bild" + i);
        }
}

function prev()
{
        if (i > 1)
        {
                i--;
                showLayer("Bild" + i);
                hideLayer("Bild" + (i+1));
                //alert("Bild"+ i);
        }
        else
        {
                i=lastPage;
                showLayer("Bild" + i);
                hideLayer("Bild" + 1);
                //alert("Bild"+ i);
        }
}

function showLayer(layerName)
{
        if(NS4)
        {
                document.layers[layerName].visibility = "show";
        }
        else
        {
                 document.all[layerName].style.visibility = "visible";
        }
}

function hideLayer(layerName)
{
        if(NS4)
        {
                document.layers[layerName].visibility = "hidden";
        }
        else
        {
                 document.all[layerName].style.visibility = "hidden";
        }
}

function dummy() {}