$(function(){
	
	var $slider = "#slider";
	var countSlid = $('li', $slider).length;
	var Width = 960;
	var maxMarginLeft = Width * -(countSlid-1);
	var position = $('ul', $slider).position();
	
	$('#btnNext',$slider).click(function(){
		position = $('ul', $slider).position();
		if(position.left > maxMarginLeft){	
			showSlid(Width);
		}
			clearInterval(play);
	});
	
	$('#btnPrev',$slider).click(function(){
		position = $('ul', $slider).position();
		if(position.left < 0){	
			showSlid(Width * -1);
		}
		clearInterval(play);
	});
	
	showSlid = function(width){
		if(!$('ul', $slider).is(':animated')){
		  $('ul', $slider).animate({
			left: '-=' + width
		  }, 700, function() {
			// Animation complete.
		  });
		}
	};
	
   changeSlid = function() {
     play = setInterval(function() {
			position = $('ul', $slider).position();
			if(position.left <= maxMarginLeft){
				width = maxMarginLeft;
			} else {
				width = Width;
			}
			showSlid(width);
     }, 4000);
   };

    changeSlid();
	
	
	
});