function navbar(n) {
var i;
var frame = top.nav.document; //if there is no frameset, use: frame = document;
var id = "navbar";		// name in navbar <img>tags; must all use the same prefix and end in a number
var path = "nav_images/";		// must end with '/'
var off_name = "navbar";
var on_name = "navbar_on";
var maxi = 6;
// reset buttons to "off"

	if (document.images) {
//	alert ("Netscape 4");
	var onbutton = frame.images[''+id+''+ n];

 for (var i = 1; i < maxi; i++) {
var offbutton = frame.images[''+id+'' + i];
var navlink = new Image();
navlink.src = path + off_name + i + ".gif";
 offbutton.src = navlink.src;
}
}

else if (document.all){
//alert ("Explorer");
var onbutton = frame.all[''+id+'' + n];

 for (var i = 1; i < maxi; i++) {
var offbutton = frame.all[''+id+'' + i];
var navlink = new Image();
navlink.src = path + off_name + i + ".gif";
 offbutton.src = navlink.src;
}
}

else if (document.getElementById) {
//alert ("Netscape 6");
var onbutton = frame.getElementById(''+id+'' + n);

 for (var i = 1; i < maxi; i++) {
var offbutton = frame.getElementById(''+id+'' + i);
var navlink = new Image();
navlink.src = path + off_name + i + ".gif";
 offbutton.src = navlink.src;
}
}

// load new "on" button

 
 var level = new Image();
level.src =  path + on_name + n + ".gif";
onbutton.src = level.src;
 
}