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


function swapPhoto(photoSRC,theCaption,theCredit,theURL) {

  try
  {
	var theImage = document.getElementById("mainPhoto");
	theImage.setAttribute("src", 'images/' + photoSRC);
	
	var displayedCaption = document.getElementById("caption");
	displayedCaption.firstChild.nodeValue = theCaption;
	
	var displayedCredit = document.getElementById("credit");

	if (theURL)
		displayedCredit.innerHTML = '<a href="' + theURL + '">' + theCredit + '</a>';
	else	
	    displayedCredit.firstChild.nodeValue = theCredit;
  }
  catch (e)
  {
  }

}