function initSwitch(){
	if (!document.getElementsByTagName) return false;
	if (!document.getElementById) return false;
	if (!document.getElementById("imagegallery")) return false;
	var gallery = document.getElementById("imagegallery");
  	var links = gallery.getElementsByTagName("a");
  	for ( var i=0; i < links.length; i++) {
    	links[i].onclick = function() {
      		showPic(this);
      		return false;
   		}
	}
}

function showPic(whichpic) {
	
	if (!document.getElementById("main-image")) return true;
	var source = whichpic.getAttribute("href");
	var placeholder = document.getElementById("main-image");
	placeholder.setAttribute("src",source);
	var gallery = document.getElementById("imagegallery");
  	var links = gallery.getElementsByTagName("a");
  	
  	for ( var i=0; i < links.length; i++) {
	  	
    	links[i].onclick = function() {
      		this.className = 'active';
      		showPic(this);
      		return false;
   		}
	}
	
	removeActive();
  	whichpic.setAttribute("id","active");
	return false;
}

function removeActive() {
	var gallery = document.getElementById("imagegallery");
	var links = gallery.getElementsByTagName("a");
	for ( var i=0; i < links.length; i++) {
		links[i].removeAttribute('id');
	}
}

addLoadEvent(initSwitch);