var browserName, browserVersion;
n = navigator.appVersion.indexOf("MSIE");
if (n != -1) {
    browserName = "MSIE";
    browserVersion = navigator.appVersion.substring(n+5,n+6);
} else if (navigator.appName == "Netscape") {
    browserName = "Netscape";
    browserVersion = parseInt(navigator.appVersion);
}
var browserIs = browserName + browserVersion;
var shouldDoRollover = ((browserName == "MSIE") && (browserVersion >= 4)) || ((browserName == "Netscape") && (browserVersion >= 3));

var foodon = new Image();
foodon.src = "prebuilt/gfx/hp/food_on.jpg";
var foodoff = new Image();
foodoff.src = "prebuilt/gfx/hp/food_off.jpg";

var dairyon = new Image();
dairyon.src = "prebuilt/gfx/hp/dairy_on.jpg";
var dairyoff = new Image();
dairyoff.src = "prebuilt/gfx/hp/dairy_off.jpg";

var bioenergyon = new Image();
bioenergyon.src = "prebuilt/gfx/hp/bioenergy_on.jpg";
var bioenergyoff = new Image();
bioenergyoff.src = "prebuilt/gfx/hp/bioenergy_off.jpg";

var poultryon = new Image();
poultryon.src = "prebuilt/gfx/hp/poultry_on.jpg";
var poultryoff = new Image();
poultryoff.src = "prebuilt/gfx/hp/poultry_off.jpg";

var sugaron = new Image();
sugaron.src = "prebuilt/gfx/hp/sugar_on.jpg";
var sugaroff = new Image();
sugaroff.src = "prebuilt/gfx/hp/sugar_off.jpg";

var cropson = new Image();
cropson.src = "prebuilt/gfx/hp/crops_on.jpg";
var cropsoff = new Image();
cropsoff.src = "prebuilt/gfx/hp/crops_off.jpg";

var horticultureon = new Image();
horticultureon.src = "prebuilt/gfx/hp/horticulture_on.jpg";
var horticultureoff = new Image();
horticultureoff.src = "prebuilt/gfx/hp/horticulture_off.jpg";

var policyon = new Image();
policyon.src = "prebuilt/gfx/hp/policy_on.jpg";
var policyoff = new Image();
policyoff.src = "prebuilt/gfx/hp/policy_off.jpg";

var livestockon = new Image();
livestockon.src = "prebuilt/gfx/hp/livestock_on.jpg";
var livestockoff = new Image();
livestockoff.src = "prebuilt/gfx/hp/livestock_off.jpg";

var pigson = new Image();
pigson.src = "prebuilt/gfx/hp/pigs_on.jpg";
var pigsoff = new Image();
pigsoff.src = "prebuilt/gfx/hp/pigs_off.jpg";

function RollOn(imgName) {
    if (document.images) {
	    document[imgName].src = eval(imgName + "on.src");
    }
}

function RollOff(imgName) {
    if (document.images) {
      document[imgName].src = eval(imgName + "off.src");
    }
}