var last="";
	var rot13map;
	function rot13init()
	{
	  var map = new Array();
	  var s   = "abcdefghijklmnopqrstuvwxyz";
	  
	  for (i=0; i<s.length; i++)
	    map[s.charAt(i)]			= s.charAt((i+13)%26);
	  for (i=0; i<s.length; i++)
	    map[s.charAt(i).toUpperCase()]	= s.charAt((i+13)%26).toUpperCase();
	  return map;
	}
	
	function rot13(a)
	{
	  if (!rot13map)
	    rot13map=rot13init();
	  s = "";
	  for (i=0; i<a.length; i++)
	    {
	      var b = a.charAt(i);
	
	      s	+= (b>='A' && b<='Z' || b>='a' && b<='z' ? rot13map[b] : b);
	    }
	  return s;
	}