<?  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;      }  }  ?>