Visual Basic - validar usuario con base de datos en SQL SERVER

codigo fuente para validar usuarios por ejemplo con access
Dim a As String
Dim B As String

Private Sub Form_Load()
StatusBar1.Panels(1).Text = "Estado:"
Data1.DatabaseName = App.Path & "\bodega.mdb"
Data2.DatabaseName = App.Path & "\bodega.mdb"
End Sub

Private Sub cmdOK_Click()
Dim access As Variant
Dim access1 As Variant
Dim r As String
Dim c As String
Dim s As String
s = "Error"
On Error Resume Next
r = txt_nombre
a = txt_nombre
Data1.RecordSource = "select * from clave where password= '" & txt_Password & "'"
Data1.RecordSource = "select * from clave where nombre= '" & txt_nombre & "'"

Data1.Refresh
If Trim(txt_Password.Text) = "" And Trim(txt_nombre.Text) = "" Then
MsgBox "Debe Ingresar Password/Nombre", vbOKOnly, Me.Caption
txt_nombre.SetFocus
Exit Sub
ElseIf Trim(txt_Password) = "" Then
MsgBox "Debe Ingresar la Password", vbOKOnly, Me.Caption
txt_Password.SetFocus
Exit Sub
ElseIf Trim(txt_nombre) = "" Then
MsgBox "Debe Ingresar el nombre", vbOKOnly, Me.Caption
txt_nombre.SetFocus
Exit Sub
End If
If Data1.Recordset.RecordCount = 1 Then
If Data1.Recordset.Fields!nombre = txt_nombre.Text And Data1.Recordset.Fields!Password = txt_Password Then
c = Data1.Recordset.Fields!grupo
Timer1.Interval = 25
ProgressBar1.Min = 0
ProgressBar1.Max = 100

Timer1.Interval = 50
StatusBar1.Panels(1).Text = "Estado: Procesando..."
access = "AUTORIZADO"
Data2.Recordset.AddNew
Data2.Recordset.Fields!nombre = txt_nombre
Data2.Recordset.Fields!Password = txt_Password
Data2.Recordset.Fields!fecha = Format(Now, "dd/mm/yyyy")
Data2.Recordset.Fields!hora = Format(Time, "hh:mm:ss ")
Data2.Recordset.Fields!Status = access
Data2.Recordset.Fields!grupo = c
Data2.UpdateRecord
Else
'este codigo es necesario cuando la password es correcta y el nombre es erroneo
MsgBox "Password/Nombre Erroneo, Acceso Denegado ", vbCritical, Me.Caption
access = "DENEGADO"
Data2.Recordset.AddNew
Data2.Recordset.Fields!nombre = r
Data2.Recordset.Fields!Password = txt_Password
Data2.Recordset.Fields!fecha = Format(Now, "dd/mm/yyyy")
Data2.Recordset.Fields!hora = Format(Time, "hh:mm:ss ")
Data2.Recordset.Fields!Status = access
Data2.Recordset.Fields!grupo = s
Data2.UpdateRecord
txt_Password.Text = ""
txt_nombre.Text = ""
txt_nombre.SetFocus
End If
Else
'este codigo se utiliza cuando la password y el nombre son erroneos
MsgBox "Password/Nombre Erroneo, Acceso Denegado ", vbCritical, Me.Caption
access = "DENEGADO"
Data2.Recordset.AddNew
Data2.Recordset.Fields!nombre = r
Data2.Recordset.Fields!Password = txt_Password
Data2.Recordset.Fields!fecha = Format(Now, "dd/mm/yyyy")
Data2.Recordset.Fields!hora = Format(Time, "hh:mm:ss ")
Data2.Recordset.Fields!Status = access
Data2.Recordset.Fields!grupo = s
Data2.UpdateRecord
txt_Password.Text = ""
txt_nombre.Text = ""
txt_nombre.SetFocus
End If
End Sub