Erreur ?

Dim connectdatabase As New MySqlConnection
        Dim command As New MySqlCommand

        connectdatabase = New MySqlConnection
        connectdatabase.ConnectionString = "server=www.db4free.net;user id=*****; password=*****; port=3306; database=*****"
        connectdatabase.Open()

        With command
            .CommandText = "INSERT INTO key_register (key, associate, date_created, date_finished) VALUES (@key,@associate,@date_created,@date_finished)"
            .Connection = connectdatabase
            .CommandType = CommandType.Text
            .Parameters.AddWithValue("@key", tb_key_register.Text)
            .Parameters.AddWithValue("@associate", tb_username.Text)
            .Parameters.AddWithValue("@date_created", Date.Now.ToString("dd/MM/yyyy"))
            .Parameters.AddWithValue("@date_finished", Date.Now.ToString("dd/MM/yyyy"))
        End With
        Try
            command.ExecuteNonQuery()
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        connectdatabase.Close()
    End Sub