In the onclick of the logon button, try something like (I'm using VB.NET):

       Dim strConn As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|userdatabase.mdb"
        Dim cn As New OleDbConnection(strConn)
        Try
            cn.Open()
            Dim cm As New OleDbCommand("SELECT COUNT(*) FROM users WHERE username=? AND password=?;", cn)
            cm.Parameters.AddWithValue("?",TextBoxUsername.Text)
            cm.Parameters.AddWithValue("?",TextBoxPassword.Text)
            Dim count As Integer = CInt(cm.ExecuteScalar())
            If(count>0) Then
                  ' user successfully logged on
                  ' do something
            Else
                 lblError.Text = "Logon failed"
            End If
        Catch ex As Exception
            lblError.Text = ex.Message()
        Finally
            cn.Close()
        End Try

Jos

Automatic translation from vb to C#:

http://labs.developerfusion.co.uk/convert/vb-to-csharp.aspx

Jos

create procedure CheckLoginDetails

(

@username  nvarchar(100),

@password nvarchar(100)

)

As

Begin

select Count(*) from tablename where Username=@username ,password=@password

End

in Codebehind Ur using Executescalar.