// DETERMINES IF IMAGE FLIPPING IS POSSIBLE
roll = (((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 3 )) || 
       ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4 )));    
	
// FUNCTION TO PRELOAD IMAGES
function preload_image(img) {
	if ( roll ) {
		var a = new Image();
		a.src = img;
		return a; 
	}
}

// FUNCTION TO FLIP IMAGES
function togglepic(imgName,imgURL) { 
	if ( roll ) {
		document.images[imgName].src = imgURL;
	}
}