getArg :: [String] -> String -> Maybe String
getArg (('-':'-':ag):v:vs) nm
     | ag == nm  = Just v
     | otherwise = getArg (v:vs) nm
getArg :: [String] -> String -> Maybe String
getArg (('-':'-':ag):v:vs) nm
     | ag == nm  = Just v
     | otherwise = getArg (v:vs) nm
getArg (('-':'-':ag):v:vs) nm
     | ag == nm  = Just v
     | otherwise = getArg (v:vs) nm