// JavaScript Document

/* following two functions are for the left menu arrows */
function show(id) { 
	document.getElementById(id).style.visibility = 'visible'; 
}

function hide(id) { 
	document.getElementById(id).style.visibility = 'hidden'; 
}

/* thumbnails on mouseover */
function lightup(img, opacity) {
	if(navigator.appName.indexOf("Netscape") != -1 && parseInt(navigator.appVersion) >=5)
    	img.style.MozOpacity = opacity/100;
 	else if (navigator.appName.indexOf("Microsoft") != -1 && parseInt(navigator.appVersion) >= 4)
    	img.filters.alpha.opacity = opacity;
}

/* change main image function added by david */
function change_image(img, desc) {	
	document.images.main.src = 'images/gallery/' + img;
	document.getElementById("desc").innerHTML = desc;		
}

// the following two functions are for text fields and the like
// they replace default values if there has been no user input

function onClicky(element, default_value) {
	if(document.getElementById(element.id).value == default_value) 
		document.getElementById(element.id).value = '';
 }
 
function  onBlury(element, default_value) {
	if(document.getElementById(element.id).value == '') 
		document.getElementById(element.id).value = default_value;
}