versOk = (((navigator.appName == "Netscape")&& 
            (parseInt(navigator.appVersion) >= 3)) ||
        
           ((navigator.appName == "Microsoft Internet Explorer")&&
            (parseInt(navigator.appVersion)>=4))
          );




function rollOn(n)
{

		   light=eval(n+"2.src");
	       if (document [n].src == light) img=true;
		   else 
		   		{
				img=false;
           		document [n].src=light;
				}

}

function rollOff(n)
{

           if (!img)
		   	  {
			  dark=eval(n+"1.src");
              document [n].src=dark;
			  }
}