<?    class encryptCalss  {  var $key=12;  function encode($txt){  for($i=0;$i<strlen($txt);$i++){  $txt[$i]=chr(ord($txt[$i])+$this->key);  }  return $txt=urlencode(base64_encode(urlencode($txt)));  }  function decode($txt){  $txt=urldecode(base64_decode($txt));  for($i=0;$i<strlen($txt);$i++){  $txt[$i]=chr(ord($txt[$i])-$this->key);  }  return $txt;  }  }    ?>