function str_rot13( str ) {	// Perform the rot13 transform on a string
	// 
	// +   original by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
	// +   improved by: Ates Goral (http://magnetiq.com)

	return str.replace(/[A-Za-z]/g, function (c) {
		return String.fromCharCode((((c = c.charCodeAt(0)) & 223) - 52) % 26 + (c & 32) + 65);
	});
}