function toggleDisplay(name)
{
    element_div=document.getElementById("div_"+name);
    element_small=document.getElementById("small_"+name);
    if(element_div.style.display=='none')
    {
        element_div.style.display='block';
        element_small.innerHTML="[weniger]";
    }       
    else
    {
        element_div.style.display='none';
        element_small.innerHTML="[mehr]";
    }
}


function index_startup()
{
    var interval=5000;
    var cycle = interval*3;
    
    var img1 = document.getElementsByName("rotate_wk1")[0];
    var img2 = document.getElementsByName("rotate_wk2")[0];
    var img3 = document.getElementsByName("rotate_wk3")[0];
    
    var imgw1 = document.getElementsByName("rotate_wkw1")[0];
    var imgw2 = document.getElementsByName("rotate_wkw2")[0];
    
    window.setTimeout(function () {
        fade(img2,img1,0);
        fade(imgw2,imgw1,0);
        window.setInterval(function () {fade(img2,img1,0); fade(imgw2,imgw1,0);}, cycle);                  
        }, interval);
        
    window.setTimeout(function () {
        fade(img3,img2,0);
        fade(imgw1,imgw2,0);
        window.setInterval(function () {fade(img3,img2,0); fade(imgw1,imgw2,0);}, cycle);                  
        }, interval*2);
        
    window.setTimeout(function () {
        fade(img1,img3,0);
        window.setInterval(function () {fade(img1,img3,0); }, cycle);                  
        }, interval*3);
}

function fade(img1,img2,step)
{
    img1.style.opacity = step/100;
    img1.style.filter = "alpha(opacity=" + step + ")"; // IE

    img2.style.opacity = (100-step)/100;
    img2.style.filter = "alpha(opacity=" + (100-step) + ")"; // IE
    
    step+=2;

    if (step <= 100) {
        window.setTimeout(function () {
            fade(img1,img2,step);
        }, 20);
    }
}