function checkBrowser()
{

    if ( navigator.appName == "Netscape" && parseInt( navigator.appVersion) >= 3)
    {
        return true;
    }

    if ( navigator.appName == "Microsoft Internet Explorer")
    {
		var sVersion;
		var nVersion;
		var nIndex;

		sVersion = new String( navigator.appVersion);
		sVersion = sVersion.substring( sVersion.indexOf( "MSIE") + 5);
		nVersion = parseInt( sVersion);

		if ( nVersion >= 4)
			return true;
    }

    return false;
}

function activatemenu( number)
{
    if ( checkBrowser() && imagesLoaded)
    {
        document[ 'menu' + number].src = "pictures/menu" + number + "on.gif";
    }
}

function inactivatemenu( number)
{
    if ( checkBrowser() && imagesLoaded)
    {
        document[ 'menu' + number].src = "pictures/menu" + number + ".gif";
    }
}

var imagesLoaded = false;

if ( checkBrowser())
{
    menu1 = new Image();
    menu1.src = "pictures/menu1.gif";
    menu1on = new Image();
    menu1on.src = "pictures/menu1on.gif";
 
    menu2 = new Image();
    menu2.src = "pictures/menu2.gif";
    menu2on = new Image();
    menu2on.src = "pictures/menu2on.gif";

    menu3 = new Image();
    menu3.src = "pictures/menu3.gif";
    menu3on = new Image();
    menu3on.src = "pictures/menu3on.gif";
 
    menu4 = new Image();
    menu4.src = "pictures/menu4.gif";
    menu4on = new Image();
    menu4on.src = "pictures/menu4on.gif";

    menu5 = new Image();
    menu5.src = "pictures/menu5.gif";
    menu5on = new Image();
    menu5on.src = "pictures/menu5on.gif";
 
    menu6 = new Image();
    menu6.src = "pictures/menu6.gif";
    menu6on = new Image();
    menu6on.src = "pictures/menu6on.gif";

    menu7 = new Image();
    menu7.src = "pictures/menu7.gif";
    menu7on = new Image();
    menu7on.src = "pictures/menu7on.gif";

    menu8 = new Image();
    menu8.src = "pictures/menu8.gif";
    menu8on = new Image();
    menu8on.src = "pictures/menu8on.gif";
 
 	imagesLoaded = true;
    
}