var bMac = (navigator.userAgent.indexOf('Mac') != -1) ? true : false; 
var bOpera = (navigator.userAgent.indexOf('Opera') != -1) ? true : false; 

function supportDblClick() {
	return (!bMac && !bOpera);
}

function navSubmit() {
	goThere(document.frmNav.url); 
	return false;
}

function swapImage(strElement, objImage) {	
// this function swaps the image identified by strElement for a new one preloaded as objImage
	if (document.images && objImage && objImage.src && objImage.src != "") {
		if (document.images[strElement]) {
			document.images[strElement].src = objImage.src;
		}
	}
}

function onFeature(num) {
	swapImage('featureNav' + num, featureNavOn[num]);
}

function offFeature() {
 	for (i = 1; i <= numberFeatures; i++) {
		swapImage('featureNav' + i, featureNavOff[i]);
	}
}