function showHideDiv(divToHide, divToShow)
{
    divToHide.style.display = "none";
    divToHide.style.visibility = "hidden";
    
    divToShow.style.display = "block";
    divToShow.style.visibility = "visible";
}

function rotateForward()
{
    //Alwats set enabled ON, so it will always stop rotation on function call.
    pauseEnabled = true;
    pauseGroupon();   
    nextGroupon();
}

function rotateBack()
{
    //Alwats set enabled ON, so it will always stop rotation on function call.
    pauseEnabled = true;
    pauseGroupon();   
    previousGroupon();
}

function previousGroupon()
{
    var oldCell = document.getElementById("grouponCell_" + currentGrouponCell);
    currentGrouponCell--;
    if (currentGrouponCell < 0)
        currentGrouponCell = maxGrouponCell;
    var newCell = document.getElementById("grouponCell_" + currentGrouponCell);
    showHideDiv(oldCell,newCell);
    
    var grouponCount = document.getElementById("grouponCount");
    grouponCount.innerHTML = (currentGrouponCell + 1) + " / " + (maxGrouponCell + 1) + "&nbsp;&nbsp;&nbsp;";
}

function nextGroupon()
{
    var oldCell = document.getElementById("grouponCell_" + currentGrouponCell);
    currentGrouponCell++;
    if (currentGrouponCell > maxGrouponCell)
        currentGrouponCell = 0;
    var newCell = document.getElementById("grouponCell_" + currentGrouponCell);
    showHideDiv(oldCell,newCell);
    
    var grouponCount = document.getElementById("grouponCount");
    grouponCount.innerHTML = (currentGrouponCell + 1) + " / " + (maxGrouponCell + 1) + "&nbsp;&nbsp;&nbsp;";
}

function pauseGroupon()
{
    if (pauseEnabled)
    {
        clearTimeout(timeOutId);
        var pauseObj = document.getElementById("buttonPause");
        pauseObj.src = "i/btn_dl_pause_dis.gif";
        pauseObj.title = "Resume Special Offer Rotation";
        pauseEnabled = false;
    }
    else
    {
        var pauseObj = document.getElementById("buttonPause");
        pauseObj.src = "i/btn_dl_pause.gif";
        pauseObj.title = "Pause Special Offer Rotation";
        pauseEnabled = true;
        //start next groupon, so it is apparent, we have started again
        rotateNext();
    }
}

function rotateNext()
{
    nextGroupon();
    timeOutId = setTimeout('rotateNext()',5000);
}