$(document).ready(function(){
	setInterval(change_ad, 10000);
});

function change_ad(){
	//advert_x //number starts as 7
	var current = $('.rotating_ads:visible');
	var current_id = current.attr('id');
	
	var x = parseInt(current_id.substr(7));
	var max = $('.rotating_ads').length;
	
	if(x == max){
		var next = 1;
	}else{
		var next = x + 1;
	}
	
	var next_id = 'advert_' + next;
	
	$('#'+current_id).fadeOut('slow');
	$('#'+next_id).fadeIn('slow');
}