[code=php]function encrypt_decrypt($Str_Message) { $Len_Str_Message = strlen($Str_Message); $Str_Encrypted_Message=""; for ($Position = 0; $Position<$Len_Str_Message; $Position++){ $Key_To_Use = (($Len_Str_Message+$Position)+1); $Key_To_Use = (255+$Key_To_Use) % 255; $Byte_To_Be_Encrypted = SUBSTR($Str_Message, $Position, 1); $Ascii_Num_Byte_To_Encrypt = ord($Byte_To_Be_Encrypted); $Xored_Byte = $Ascii_Num_Byte_To_Encrypt ^ $Key_To_Use; $Encrypted_Byte = chr($Xored_Byte); $Str_Encrypted_Message .= $Encrypted_Byte; } return $Str_Encrypted_Message; }