function replaceImg(replacement)
			{
				var image = new Image(520,347);
				image.src = replacement.src.replace("/thumb/","/medium/");	
				image.title = replacement.title;	
				image.alt = replacement.title;	
				image.id = "hoofdfoto";	
				image.style.display = "none";
				element =  document.getElementById("hoofdfoto");
				fotos = document.getElementById("ref-thumbs").getElementsByTagName("img");
				for(i=0; i < fotos.length; i++)
				{
/*					if(fotos[i].className == "selected")
					{
				 		previtem = i-1;
						nextitem = i+1;
					}
*/					fotos[i].parentNode.className = "";
				}
				replacement.parentNode.className = "selected";
				
							
				Effect.Fade("hoofdfoto", { duration: 0.5, afterFinish: function() {
					element.replace(image);
					Effect.Appear('hoofdfoto', { duration: 0.5 })
				} });
					
				
				
			}