function getFileExtension(filename)
{
  var ext = /(^.+)\.([^.]+)$/.exec(filename);
  return ext;
}


	var prepare_slider = function(){
		
		var x_pos = 0;
		var li_items_n = 0;	
		var right_clicks = 0;
		var viewWindow = 5;
		var left_clicks = 0;
		
		var li_col = $('slider_list').getElements('li');
	
		li_col.each(function(li, index){
			size = li.getSize();
			x_pos += size.x;
			li_items_n++;
			li.getElement('img').setStyle('cursor','pointer');
			li.getElement('img').addEvent('click', function(){
																	
					image_source = li.getElement('img').get('src');
					ext = getFileExtension(image_source);
					
					

			})
			
		
		
		})
		
		right_clicks = li_items_n - viewWindow;
		total_clicks = li_items_n - viewWindow;
		
		$('slider_list').setStyle('position','relative');
		$('slider_list').setStyle('left','0px');
		$('slider_list').setStyle('width', x_pos+'px');
		
		var myFx = new Fx.Tween($('slider_list'), {transition: Fx.Transitions.Sine.easeOut, duration:700});
		myFx.addEvent('start', function(){ is_playing = true; });
		myFx.addEvent('complete', function(){ is_playing = false; });
	
		var is_playing = false;

		$('left_but').addEvent('click', function(){
												 
			if (!is_playing)									 {
			cur_offset = $('slider_list').getStyle('left').toInt();
			if (left_clicks > 0) { myFx.start('left',   cur_offset + 181 + 'px'); right_clicks++; left_clicks--;} else { myFx.start('left',    -181*total_clicks	+ 'px'); right_clicks = 0; left_clicks = total_clicks;}
			}
		});

		$('right_but').addEvent('click', function(){
												  if (!is_playing)									 {
			
			cur_offset = $('slider_list').getStyle('left').toInt();
			
			 if (right_clicks > 0) { myFx.start('left', cur_offset - 181 + 'px'); right_clicks--; left_clicks++; } else { myFx.start('left',    0	+ 'px'); left_clicks = 0; right_clicks = total_clicks;}
			 
												  }
			 });	
		
	}