var logominibelt_of = new Image();
		var logominibelt_on = new Image();
		var logoslitta_of = new Image();
		var logoslitta_on = new Image();
		var logonastro_of = new Image();
		var logonastro_on = new Image();
		var logolubri_of = new Image();
		var logolubri_on = new Image();
		
			
		function PreLoad(){
			logominibelt_of.src = "images/logominibelt_of.gif";
		  logominibelt_on.src = "images/logominibelt_on.gif";
		  logoslitta_of.src = "images/logoslitta_of.gif";
		  logoslitta_on.src = "images/logoslitta_on.gif";
		  logonastro_of.src = "images/logonastro_of.gif";
		  logonastro_on.src = "images/logonastro_on.gif";
		  logolubri_of.src = "images/logolubri_of.gif";
		  logolubri_on.src = "images/logolubri_on.gif";
		}


		var ImgName;
		 
		function Scambia(nameimg){
		 ImgName = nameimg;
		 if (eval('document.' + nameimg + '.complete')&&eval('document.' + nameimg + '_img.complete')){
			 ImgOn();
		 }
		}
		
		function ImgOn(){
			if (CheckImgLoad_on(ImgName)){
				eval('document.' + ImgName + '.src=' + ImgName + '_on.src;');
			}else{
				eval("setTimeout('ImgOn()', 1);");
			}
		}
		
		function Ripristina(nameimg){
		ImgName = nameimg;
		ImgOf();
		}
		
		function ImgOf(){
			if (CheckImgLoad_of(ImgName)){
				eval('document.' + ImgName + '.src=' + ImgName + '_of.src;');
			}else{
				eval("setTimeout('ImgOf()', 1);");
			}
		}
		
		function CheckImgLoad_on(nameimg){
  		if (!(document.layers)){
  			if (eval(nameimg + '_on.complete')){
  				 return true;
  			}else{
  				 return false;
  			}
  		}else{
				return true;
  		}		
		}
		
		function CheckImgLoad_of(nameimg){
  		if (!(document.layers)){
  			if (eval(nameimg + '_of.complete')){
  				return true;
  			}else{
  				return false;
  			}
  		}else{
				return true;
  		}	
		}