function swap(targetId){
  
  if (document.getElementById)
        {
        target = document.getElementById(targetId);
        
            if (target.style.display == "none")
                {
                target.style.display = "";
                } 
            
            else 
                {
                target.style.display = "none";
                }
                
        }
}



// swap image and scroll screen 

function swapPhoto(photoSRC) {
    document.images.imgPhoto.src = "img/collections/rings/" + photoSRC;
}