window.addEvent('domready', function() {
	var content_pos=0;
	var increment=450;
    if(!$('content_inner')) return;

	var max_pos=$('content_inner').getStyle('height').toInt();
	var upward=$('upward');
	var downward=$('downward');
	if(upward&&downward){
		var scroll = new Fx.Scroll('content_outer', {
			wait: false,
			duration: 1000,
			transition: Fx.Transitions.Quad.easeInOut
		});
		downward.addEvent('click',function(event){
			if(content_pos<max_pos)
			{
				event = new Event(event).stop();
				content_pos+=increment;
				if(content_pos>max_pos)content_pos=max_pos;
				scroll.scrollTo(0,content_pos);
			}
			if(content_pos<max_pos){			
				downward.setStyle('visibility','visible');
			}else{
				downward.setStyle('visibility','hidden');
			}
			if(content_pos>0){
				upward.setStyle('visibility','visible');
			}else{
				upward.setStyle('visibility','hidden');			
			}
		});
		upward.addEvent('click',function(event){
			if(content_pos>0)
			{			
				event = new Event(event).stop();
				content_pos-=increment;
				if(content_pos<0)content_pos=0;
				scroll.scrollTo(0,content_pos);			
			}
	
			if(content_pos<max_pos){
				downward.setStyle('visibility','visible');
			}else{
				downward.setStyle('visibility','hidden');
			}
			if(content_pos>0){
				upward.setStyle('visibility','visible');
			}else{
				upward.setStyle('visibility','hidden');			
			}
		});
	}
});