function showNewLayer(layerID)
    {
        switch(layerID)
        {
        case 1:
        {
            document.all.divLayer1.style.display="";
            document.all.divLayer2.style.display="none";
            document.all.divLayer3.style.display="none";
            document.all.divLayer4.style.display="none";
            
            document.all.divImg1.src="images/b1_1.gif";
            document.all.divImg2.src="images/b2.gif";
            document.all.divImg3.src="images/b3.gif";
            document.all.divImg4.src="images/b4.gif";

        }
        break;
        case 2:
        {
            document.all.divLayer1.style.display="none";
            document.all.divLayer2.style.display="";
            document.all.divLayer3.style.display="none";
            document.all.divLayer4.style.display="none";
            
            document.all.divImg1.src="images/b1.gif";
            document.all.divImg2.src="images/b2_1.gif";
            document.all.divImg3.src="images/b3.gif";
            document.all.divImg4.src="images/b4.gif";

        }
        break;
        case 3:
        {
            document.all.divLayer1.style.display="none";
            document.all.divLayer2.style.display="none";
            document.all.divLayer3.style.display="";
            document.all.divLayer4.style.display="none";
            
            document.all.divImg1.src="images/b1.gif";
            document.all.divImg2.src="images/b2.gif";
            document.all.divImg3.src="images/b3_1.gif";
            document.all.divImg4.src="images/b4.gif";

        }
        break;

        case 4:
        {
            document.all.divLayer1.style.display="none";
            document.all.divLayer2.style.display="none";
            document.all.divLayer3.style.display="none";
            document.all.divLayer4.style.display="";
            
            document.all.divImg1.src="images/b1.gif";
            document.all.divImg2.src="images/b2.gif";
            document.all.divImg3.src="images/b3.gif";
            document.all.divImg4.src="images/b4_1.gif";

        }
        break;

        }

    }