$(document).ready(function() {
	
	//grab the width and calculate left value
	var item_width = $('#slide li').outerWidth(); 
	var left_value = item_width * (-1); 
        
    //move the last item before first item, just in case user click prev button
	$('#slide li:first').before($('#slide li:last'));
	
	//set the default item to the correct position 
	$('#slide ul').css({'left' : left_value});

 
    //if user clicked on next button
	function copa() {

		//get the right position
		var left_indent = parseInt($('#slide ul').css('left')) - item_width;
		
		//slide the item
		$('#slide ul:not(:animated)').animate({'left' : left_indent}, 1500, function () {
            
            //move the first item and put it as last item
			$('#slide li:last').after($('#slide li:first'));                 	
			
			//set the default item to correct position
			$('#slide ul').css({'left' : left_value});
		
		});
		         
		//cancel the link behavior
		return false;
		
	};        
	
	var speed = 6000;
    setInterval(function() {
   		copa();
	}, speed);

});