function showPic (whichpic) {
  if (!document.getElementById) return true;
	
	// reset rollovers to inactive state
  var menu = document.getElementById("nav");
  var rolloverOff = menu.getElementsByTagName("a");
  for ( var i=0; i < rolloverOff.length; i++) {
    rolloverOff[i].className = 'inactive';
	}
	
	whichpic.className = 'active';
	return false;
}
function hidePic (whichpic) {
  if (!document.getElementById) return true;
	
	// reset rollovers to inactive state
  var menu = document.getElementById("nav");
  var rolloverOff = menu.getElementsByTagName("a");
  for ( var i=0; i < rolloverOff.length; i++) {
    rolloverOff[i].className = 'inactive';
	}
	return false;
}
function prepareRollover() {
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("content")) return false;
  var menu = document.getElementById("nav");
  var links = menu.getElementsByTagName("a");
  for ( var i=0; i < links.length; i++) {
    links[i].onmouseover = function() {
      return showPic(this);
    }
  }
  for ( var i=0; i < links.length; i++) {
    links[i].onmouseout = function() {
      return hidePic(this);
    }
  }
}