function prepareGallery(){
  if( document.getElementById &&
      document.getElementsByTagName ){
    if( document.getElementById( 'imagelist' ) ){
      var gallery = document.getElementById( 'imagelist' );
      var links = gallery.getElementsByTagName( 'a' );
      for( var i=0; i < links.length; i++ ){
        links[i].onclick = function(){
          return showPic(this);
        };
      }
      firstPic();
    }
  }
}

function firstPic(){
  if( document.getElementById &&
      document.getElementsByTagName ){
    if( document.getElementById( 'imagelist' ) ){
      var gallery = document.getElementById( 'imagelist' );
      var links = gallery.getElementsByTagName( 'a' );
      
          showPic(links[0]);
       
      }
    }
  
}

function showPic (whichpic) { 

	if (document.getElementById) { 
		document.getElementById('placeholder').src = whichpic.href; 
		if (whichpic.title) { 
			document.getElementById('caption').childNodes[0].nodeValue = whichpic.title; 
		} else { 
			document.getElementById('caption').childNodes[0].nodeValue = whichpic.childNodes[0].nodeValue; 
		}
		
		activeLink(whichpic);
				
		return false; 
	} else { 
		return true; 
	} 
}


function activeLink(whichpic){
  if( document.getElementById &&
      document.getElementsByTagName ){
    if( document.getElementById( 'imagelist' ) ){
      var gallery = document.getElementById( 'imagelist' );
      var links = gallery.getElementsByTagName( 'a' );
      for( var i=0; i < links.length; i++ ){
        links[i].setAttribute('class','passiveNumber');
       
      }
      whichpic.setAttribute('class','activeNumber');
    }
  }
}