// Set window.onload functions
addLoadEvent(prepareGallery);

// addLoadEvent by Simon Willison (http://simon.incutio.com/)
function addLoadEvent(func) {
  	var oldonload = window.onload;
  	if (typeof window.onload != 'function') {
    	window.onload = func;
		} else {
	  	window.onload = function() {
		    oldonload();
	  		func();
	  	}
	}
}

// Assign onclick properties to all gallery links
function prepareGallery() {
  	if (!document.getElementsByTagName) return false;
  	if (!document.getElementById) return false;
  	if (!document.getElementById("navGallery")) return false;
	var gallery = document.getElementById("navGallery");
	var links = gallery.getElementsByTagName("a");
	for (var i=0; i<links.length; i++) {
	  links[i].onclick = function () {
	    return showPic(this);
	  }
	  
	}
}

// Change gallery image, alt and paragraph description
function showPic(whichpic) {
	if (!document.getElementById("placeholder")) return true;
	var source = whichpic.getAttribute("href");
	var placeholder = document.getElementById("placeholder");
	placeholder.setAttribute("src",source);
	
  if (whichpic.getAttribute("title")) {
   	var text = whichpic.getAttribute("title");
	} else {
   	var text = "";
	}
	placeholder.setAttribute("alt",text);
	
	var gallery = document.getElementById("navGallery");
	var links = gallery.getElementsByTagName("a");
  	for (var i=0; i<links.length; i++) {
	  links[i].className = "";
	}
	whichpic.className = "selected";
 	return false;		
}