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


	var prepare_slider = function(){
		
		var x_pos = 0;
		var li_items_n = 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);
					
					

			})
			
			
		})
		
		$('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(){
			cur_offset = $('slider_list').getStyle('left').toInt();
			if (!is_playing && ((cur_offset + 181) <= 0)) myFx.start('left',   cur_offset + 181 + 'px');
		});

		$('right_but').addEvent('click', function(){
			var is_playing = false;
			cur_offset = $('slider_list').getStyle('left').toInt();
			
			if (!is_playing && ((cur_offset - 181) >= -(181*2) )) myFx.start('left', cur_offset - 181 + 'px'); 
		});	
	}