var Popup = {
	
	init : function( box, sfondo ) {
		
		box.setStyle('opacity','0');
		box.setStyle('display','none');
		
		Popup.showBox( box );
		
	},
	
	/**
	* metodi che fanno apparire
	* o nascondere i box
	*/
	
	showBox : function( box ) {
		
		box.setStyle('display','block');
		box.tween('opacity','1');
	
	},
	
	hideBox : function( box ) {
		
		box.setStyle('display','none');
		box.tween('opacity','0');
	
	}

};