function replace_site_content(url){
	
	var _url = url;
	
	/*new Effect.Opacity('site_content', {from: 1, to: 0, afterFinish: function(){
										 Effect.BlindUp('site_content', {afterFinish: function(){ 
										
										$('site_content').innerHTML =  "<div class='loader'>LOADING</div>";
										Effect.BlindDown('site_content');
										new Effect.Opacity('site_content', {from: 0, to: 1, duration: 0.5});
										 requestContent(url)}})
										 
										} 
					   					});*/
	
	
new Effect.Parallel([
	Effect.BlindUp('site_content', {sync: true}),
	 new Effect.Opacity('site_content', {sync: true, from: 1, to: 0})
	 ], {duration:2, afterFinish: function(){
				requestContent(url);	
				new Effect.Parallel([
				Effect.BlindDown('site_content', {sync: true}),
				 new Effect.Opacity('site_content', {sync: true, from: 0, to: 1})
	 			], {duration:2});	
	}});
	
	

}

function requestContent (url){

		new Ajax.Request(url, {
		   onComplete: function(transport) {
		
				var textResponse = transport.responseText;
				var start_string = "<!-- AJAX REPLACE START -->";
				var end_string = "<!-- AJAX REPLACE END -->";
				var start = textResponse.indexOf(start_string);
				var end = textResponse.indexOf(end_string);
				var replacement = textResponse.slice(start, end);  
				
				new Effect.Opacity('site_content', {from: 1, to: 0, duration: 0.5, afterFinish: function(){
														$('replacement_area').innerHTML =  replacement;	
														new Effect.Opacity('site_content', {from: 0, to: 1});
														}
													});
				
	 		}
	}); 
}