// show an email link on a page in a way that spam harvesters can't see

	function show_email(user, domain, tld, label) {
		if (!label) { label = user + "@" + domain + "." + tld; }
		document.write("<a href='mailto:" + user + "@" + domain + "." + tld + "'>" + label + "<\/a>");
	}


// show either the Command or Control text depending on the platform

	function show_command_key() {
		key = (navigator.platform.indexOf("Win") != -1) ? "Control" : "Command" ;
		document.write(key);
	}


// figure out whether a variable has been set or not without generating an undefined error if it hasn't
// possible types are "undefined", "object", "boolean", "number", "string" or "function", with everything else being "object"
// this does not work on function arguments inside a function; even if the argument is set, this still returns false
// but in that case we can just check for a value without getting an error

	function isset(variable, type) {
		if (type) {
			eval("result = (typeof(" + variable + ") == type)");
		} else {
			eval("result = (typeof(" + variable + ") != 'undefined')");
		}
		return result;
	}