var scrW;
var scrH;
scrW = screen.width / 2;
scrH = screen.height / 2;

var navMax = 19;
var navOver = new Array(navMax);
var navOut = new Array(navMax);
for (var z=1; z<=navMax; z++) {
	navOver[z] = new Image();
	navOut[z] = new Image();
	navOver[z].src = "images/nav_on" + z + ".gif";
	navOut[z].src = "images/nav_off" + z + ".gif";
}

function switchImg(varID, varSrc, varWhich) {
	if (varWhich) {
		document.images[varID].src = navOver[varSrc].src;
	} else {
		document.images[varID].src = navOut[varSrc].src;
	}
}

function openWin(gotoURL,winName,winW,winH,scrollers) {
	window.open(gotoURL,winName,'width=' + winW + ',height=' + winH + ',top=' + (scrH-(winH/2)) + ',left='+ (scrW-(winW/2)) +',toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=' + scrollers + ',resizable=yes');
}