Protected Sub Blocca()
        Dim mdbCon As New MySql.Data.MySqlClient.MySqlConnection()
        Dim dr As MySql.Data.MySqlClient.MySqlDataReader
        Dim constring As String, queryString As String

        constring = "Server=" & SERVER_CONNESSIONE & ";Database=" & DB & ";User id=" & USER & ";Pwd=" & PSW & ";Port=" & PORT & ";"

        mdbCon.ConnectionString = constring

        queryString = "LOCK TABLES Protocolli READ;"

        Dim command As New MySql.Data.MySqlClient.MySqlCommand(queryString, mdbCon)
        command.Connection.Open()

        command.ExecuteReader()

        mdbCon.Close()

    End Sub