bName = navigator.appName;
bVer = parseInt(navigator.appVersion);

if ((bName == "Netscape" && bVer >= 3) || (bName == "Microsoft Internet Explorer" && bVer >= 4)) {
   	 br = "n3";
} else {
  	br = "n2";
}

// Create image objects, preload all active and inactive images.
if (br == "n3") {
	var img1on = new Image();
	img1on.src = "images/meet_r.gif";
	var img2on = new Image();
	img2on.src = "images/about_r.gif";
	var img3on = new Image();
	img3on.src = "images/patient_r.gif";
	var img4on = new Image();
	img4on.src = "images/helpful_r.gif";
	var img5on = new Image();
	img5on.src = "images/research_r.gif";

	var img1off = new Image();
	img1off.src = "images/meet.gif";
	var img2off = new Image();
	img2off.src = "images/about.gif";
	var img3off = new Image();
	img3off.src = "images/patient.gif";
	var img4off = new Image();
	img4off.src = "images/helpful.gif";
	var img5off = new Image();
	img5off.src = "images/research.gif";
}

// Function to "activate" images.
function imgAct(imgName) {
    if (br == "n3") {
	    document[imgName].src = eval(imgName + "on.src");
    }
}

// Function to "deactivate" images.
function imgInact(imgName) {
    if (br == "n3") {
	    document[imgName].src = eval(imgName + "off.src");
    }
}