Solo como comentario podría colocarlo tambien de ésta forma:
Cita: If txtContra.Text = "" And txtUsu.Text = "" Then
MsgBox("ERROR: DEBE INTRODUCIR ALGUN DATO", MsgBoxStyle.Exclamation)
VaciarControles()
Exit Sub
End If
Dim strConexion As String = "Provider=Microsoft.Jet.OLEDB.4.0;User ID=Admin;Data Source=C:\BD.mdb;"
conexion = New OleDbConnection(strConexion)
conexion.Open()
Dim strComan As String = "SELECT Usuario, Password FROM Usuarios WHERE Usuario = '" & txtUsu.Text & "'" & " AND Password = '" & txtContra.Text & "'"
Dim coman As New OleDbCommand(strComan, conexion)
Dim resul As OleDbDataReader
Dim inicio As New Form1
resul = coman.ExecuteReader()
Dim blnOK as Boolean = False
If resul.Read() Then
blnOk = True
End If
resul.Close()
conexion.Close()
If Not blnOK
MsgBox("ERROR: USUARIO Y/O CONTRASEÑA INCORRECTOS", MsgBoxStyle.Critical)
VaciarControles()
Else
psUsuario = txtUsu.Text
psContra = txtContra.Text
inicio.Show()
Me.Hide()
End If
End Sub
Salu2