var Menu = Class.create();
Menu.prototype = {
	// Constructor
	// Available parameters : 
	// arImg :  Array[] con nomi image contenenti il placeHolder: #onoff# 
	// urlImg : url images
	// parUrlImg : parametri dell' Url Images
	// prefixIDImg : prefisso per costruire l'id dell'oggetto DOM images
	// imgON : stringa che identifica imgON
	// imgOFF : stringa che identifica imgOFF
	// parUrlImg : i parametri dell'UrlImg	
	initialize: function(p) {
		
		this.tagOnOff = "#onoff#";
		this.imgON = p.imgON;		
		this.imgOFF = p.imgOFF;
	  	this.arUrlImg = p.arUrlImg;
		//this.urlImg = p.urlImg;
		this.prefixIDImg = p.prefixIDImg;
		this.nImg = p.arUrlImg.length;
		//this.parUrlImg = p.parUrlImg;
		this.preloadImages();		
	},	
	preloadImages:  function(){		
		var preloadimg = [];	    
	    var i = 0;  
	    for(i=0; i<this.nImg; i++) {
			var u = this.arUrlImg[i];
			preloadimg[i] = new Image();			
			preloadimg[i].src = u.replace(this.tagOnOff,this.imgON); 
		}		
	},	
	rlover: function(id){
		var u = this.arUrlImg[id];		
		$(this.prefixIDImg + id).src = u.replace(this.tagOnOff,this.imgON);  
	},	
	rlout: function(id){
		var u = this.arUrlImg[id];
		$(this.prefixIDImg + id).src = u.replace(this.tagOnOff,this.imgOFF);  
	}	
}