var flag = true;
var state = 0;

function toggleFlag() {
    if (flag) {
        flag = false;
    } else {
        flag = true;
    }
}

function toggle() {
    var layer1 = document.getElementById("rolling1");
    var layer2 = document.getElementById("rolling2");
    var layer3 = document.getElementById("rolling3");
    
    
    switch (state) {
    case 0:
        layer2.style.display = 'none';
        layer3.style.display = 'none';
        layer1.style.display = 'block';
        break;
     case 1:
        layer3.style.display = 'none';
        layer1.style.display = 'none';
        layer2.style.display = 'block';
        break;
     case 2:
        layer1.style.display = 'none';
        layer2.style.display = 'none';
        layer3.style.display = 'block';
        break;
     }
     state++;
     if (state >= 3) {
         state -= 3;
     }
}

function toggling() {
    if (flag) {
        toggle();
    }
    window.setTimeout('toggling()', 10000);
}