C# / VB.NET - Mysql - Login md5

Salve ragazzi
Non riesco a creare un login md5 mysql potete aiutarmi?

Imports System.Security.Cryptography
Imports MySql.Data.MySqlClient
Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       Dim conn As MySqlConnection
        conn = New MySqlConnection
        conn.ConnectionString = "server=localhost;" & "user id=root;" & "password=12345;" & "database=protezione"  'Server data

        Try
            conn.Open() ' open the connection
        Catch myerror As MySqlException
            MsgBox("Impossibile connettersi al database: " & myerror.Message.ToString) ' catch the error
        End Try

        Dim user As String = txtID.Text
        Dim pass As String = MD5StringHash(txtPW.Text)

        Dim myAdapter As New MySqlDataAdapter
        Dim SQLQuery As String = "SELECT * FROM user WHERE Username='" + Replace(user, "", "") + "' AND Password='" + Replace(pass, "", "") & "'" ' Das ist die Abfrage welche Prüft ob der Account existiert.Die txt_benutzer ist die Textbox in der der Benutzername eingeben wird und txt_passwort bekommt das Passwort
        Dim myCommand As New MySqlCommand
        myCommand.Connection = conn
        myCommand.CommandText = SQLQuery

        myAdapter.SelectCommand = myCommand
        Dim myData As MySqlDataReader
        myData = myCommand.ExecuteReader() ' start query
        If myData.HasRows Then ' if the pw/id is correct
            MsgBox("Accesso Consentito.")
            conn.Close()
            conn.Open()

        Else 'Display error
            MsgBox("Accesso Negato")
        End If

    End Sub

End Class

Il modulo:

Imports System.Security.Cryptography
Imports System.Text
Module md5

    Public Function MD5StringHash(ByVal strString As String) As String
        Dim MD5 As New MD5CryptoServiceProvider
        Dim Data As Byte()
        Dim Result As Byte()
        Dim Res As String = ""
        Dim Tmp As String = ""

        Data = Encoding.ASCII.GetBytes(strString)
        Result = MD5.ComputeHash(Data)
        For i As Integer = 0 To Result.Length - 1
            Tmp = Hex(Result(i))
            If Len(Tmp) = 1 Then Tmp = "0" & Tmp
            Res += Tmp
        Next
        Return Res
    End Function

End Module

In rete tutti usano questo codice.. ma quando inserisco la pass mi dice accesso negato.
Grazie in anticipo