$(document).ready(function() {
				
				defaultWidth	= 320; //pixels
				transition		= 500; //millisecond
				
				function resetMargin(width) {
						
					divLeftMargin	= 0;
				
					$('.additional-block').each(function() {
						
						thisLeftMargin	= divLeftMargin + 'px';
						
						$(this).css('margin-left', thisLeftMargin);
						
						divLeftMargin	= divLeftMargin + width;
						
					});
				}
				
				resetMargin(defaultWidth);
				
				$('.menu a').each(function() {
					
					thisHref	= $(this).attr('href');
					
					if($(thisHref).length > 0) {
						$(this).addClass('has-child');
					}
					
				});
				
				$('.menu a').click(function(event) {
					
					event.preventDefault();
					
					selectedDiv			= $(this).attr('href');
					selectedMargin		= $(selectedDiv).css('margin-left');
					selectedParent		= $(this).parents('.additional-block');
					sliderMargin		= $('.slider').css('margin-left');
					slidingMargin		= (parseInt(sliderMargin) - defaultWidth) + 'px';
					
					
					if(selectedMargin.length > 0) {
						
						$(selectedDiv).children('.header').prepend('<span class="back"></span>').bind('click', function () {
					
							selectedParent	= $(this).parents('.additional-block');
							sliderMargin	= - (parseInt(selectedParent.css('margin-left')) - defaultWidth) + 'px';
							$('.slider').animate({marginLeft: sliderMargin}, transition);
							
						});
							
						if((parseInt(selectedMargin) - defaultWidth) >= defaultWidth) {
						
							selectedParent.after($(selectedDiv));
							
							resetMargin(defaultWidth);
						
							$('.slider').animate({marginLeft: slidingMargin}, transition);
						
						} else {
						
							$('.slider').animate({marginLeft: slidingMargin}, transition);
					
						}
					}
				});
				
			});