function InvertVisibility(roll_id) {
	if (document.getElementById(roll_id).style.display=='none') {
		document.getElementById(roll_id).style.display=''; return true;
	} else {
		document.getElementById(roll_id).style.display='none'; return false;
	}
}

function SwapImage(themedir, img_id, img1, img2) {
	if (document.getElementById(img_id).src.substring(document.getElementById(img_id).src.lastIndexOf('/') + 1,document.getElementById(img_id).src.length)==img1.replace(/^.*\//gi, '')) {
		document.getElementById(img_id).src = themedir + '/images/' + img2;
	} else {
		document.getElementById(img_id).src = themedir + '/images/' + img1;
	}
}

/* merge with cookie.js:GetCookie() ? */
function Get_Cookie(name) {
	var start = document.cookie.indexOf(name+"=");
	var len = start+name.length+1;
	if ((!start) && (name != document.cookie.substring(0,name.length))) return null;
	if (start == -1) return null;
	var end = document.cookie.indexOf(";",len);
	if (end == -1) end = document.cookie.length;
	return unescape(document.cookie.substring(len,end));
}

/* merge with cookie.js:SetCookie() ? */
function Set_Cookie(name,value,expires,path,domain,secure) {
	document.cookie = name + "=" +escape(value) +
	( (expires) ? ";expires=" + expires.toGMTString() : "") +
	( (path) ? ";path=" + path : "") + 
	( (domain) ? ";domain=" + domain : "") +
	( (secure) ? ";secure" : "");
}

function UpdateCookie(roll_id) {
	var cookie = Get_Cookie("RollPreferences");
	var new_cookie = '';
	if (cookie != null) {
		var splitCookie = cookie.split(":");
		var size = splitCookie.length - 1;
		for (var i = 0; i < size; i++) {
			if (splitCookie[i] != roll_id) {
				new_cookie = new_cookie + splitCookie[i] + ":";
			}
		}
		if (new_cookie == cookie) {
			new_cookie = cookie + roll_id + ":";
		}
		Set_Cookie("RollPreferences", new_cookie, "", "/");
	} else {
		new_cookie = roll_id + ":";
		Set_Cookie("RollPreferences", new_cookie, "", "/");
	}
					
}