var promoBanners = Class.create();
	promoBanners.prototype =
	{
		initialize: function( container_id, tag_name, class_name, expires )
		{
			this.initialized = false;
			this.container = $(container_id);
			if( ! this.container )
			{
				return false;
			}

			this.elements = $A( this.container.getElementsByTagName( tag_name ) );
			if( ! this.elements )
			{
				return false;
			}

			this.expires = ( expires ) ? parseInt(expires) : 30;
			this.class_name = class_name;

			this.interval  = null;
			this.max_loop = null;
			this.current_loop = 0;

			this.max = this.elements.length - 1;
			this.cookie = container_id + '_last_index';

			this.last_index = Cookie.get( this.cookie );
			this._next();

			for( var i=0; i<=this.max; i++ )
			{
				if( i != this.last_index )
				{
					Element.addClassName( this.elements[i], this.class_name );
				}
			}
			this.initialized = true;

			return true;
		},

		_next: function()
		{
			if( this.last_index == null )
			{
				this.last_index = Math.round( Math.random() * this.max );
			}
			else
			{
				this.last_index = parseInt(this.last_index);
				if( this.last_index == this.max )
				{
					this.last_index = 0;
				}
				else
				{
					++this.last_index;
				}
			}

			if( this.last_index < 0 || this.last_index > this.max )
			{
				this.last_index = Math.round( Math.random() * this.max );
			}
			Cookie.set( this.cookie, this.last_index, this.expires );
			return true;
		},

		_toggle: function()
		{
			Element.addClassName( this.elements[this.last_index], this.class_name );
			this._next();
			Element.removeClassName( this.elements[this.last_index], this.class_name );
			if( this.max_loop )
			{
				++this.current_loop;
				if( this.current_loop >= this.max_loop )
				{
					if( this.interval ) clearInterval(this.interval);
				}
			}
			return true;
		},

		_play: function( time_interval, max_loop )
		{
			if( !this.initialized  )
			{
				return false;
			}
			this.interval = setInterval( this._toggle.bind(this), time_interval*1000 );
			if( parseInt(max_loop) )
			{
				this.max_loop = (this.max+1)*max_loop;
			}
			return true;
		}
	}