function showPic(whichpic,placeHolderId,paragraphID) {
  var source = whichpic.getAttribute("src");
  var placeholder = document.getElementById(placeHolderId);
  placeholder.setAttribute("src",source);
  var text = whichpic.getAttribute("alt");
  var description = document.getElementById(paragraphID);
  description.firstChild.nodeValue = text;
}