var Sitemap = {
	scrollUp:	function(count, max_count) {
		element = document.getElementById('sitemap');
		if (!element.current_index)
			element.current_index = 0;
			
		if (element.current_index <= 0)
			return;
	
		element.current_index--;
		document.getElementById('sitemap_btn_top').style.visibility  = element.current_index > 0 ? 'visible' : 'hidden';
		document.getElementById('sitemap_btn_down').style.visibility  = element.current_index * max_count >= count ? 'hidden' : 'visible';

		new Effect.Move(element, {
			y:		-(element.current_index * 138),
			mode:	'absolute'
		});
	},
	
	scrollDown:	function(count, max_count) {
		element = document.getElementById('sitemap');
		if (!element.current_index)
			element.current_index = 0;
			
		if (element.current_index + max_count >= count) {
			return;
		}
	
		element.current_index++;
		document.getElementById('sitemap_btn_top').style.visibility  = element.current_index > 0 ? 'visible' : 'hidden';
		document.getElementById('sitemap_btn_down').style.visibility  = (element.current_index+1) * max_count >= count ? 'hidden' : 'visible';
		
		new Effect.Move(element, {
			y:		-(element.current_index * 138),
			mode:	'absolute'
		});
	}
}