function ShowImage(id)
{
    var factor = parseInt(document.getElementById("imageFactor").value); 
    document.getElementById("mainImage").src = "Gallery/" + (factor + id) + ".jpg";
}

function ViewPage(action)
{
    var imageId;
    var maxImages = 83;
    var maxPages = Math.floor((maxImages/24)) + 1;

    var currentPage = parseInt(document.getElementById("currentPage").value); 
    var newPage = currentPage + action;
    var factor = newPage * 24;

    if ((newPage < maxPages) && !(currentPage == 0 && action == -1))
    {
        for (i=1; i<25; i++)
        {
            imageId = factor + i;
            
            if (imageId <= maxImages)
            {
                document.getElementById("image" + i).src = "Gallery/Thumb/" + imageId + ".jpg";
                document.getElementById("image" + i).style.display = "inline";
                document.getElementById("galleryNext").style.display = "inline";
            }
            else
            {
                document.getElementById("image" + i).style.display = "none";
                document.getElementById("galleryNext").style.display = "none";
            }
        }
        
        document.getElementById("currentPage").value = newPage;
        document.getElementById("imageFactor").value = factor;
    }
    
    if((newPage -1) < 0)
        document.getElementById("galleryPrevious").style.display = "none";
    else
        document.getElementById("galleryPrevious").style.display = "inline";
        
}