Need help fixing my Login Code in Visual Basic

[pkminer30]

My visual basic code is:

Public Class Form1

    Dim PasswordTrials As Integer

    Private Property TextPassword As Object

    Private Property TextUsername As Object

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Login = Me.ClientsTableAdapter1.ClientQuery(TextUsername.Text, TextPassword.Text)

        If Login Is Nothing Then
            MsgBox("Please Enter Your Login Details", MsgBoxStyle.Critical)
            TextUsername.Value = ""
            TextPassword.Value = ""
            PasswordTrials = PasswordTrials + 1
            If PasswordTrials >= 3 Then
                MsgBox("Login Attempts Exceeded, Spreadsheet Shutting Down", MsgBoxStyle.Critical)
                End
            End If
        Else
            MsgBox("Login Successful, You Can Now Access The Spreadsheet", MsgBoxStyle.Information)
            End
        End If
    End Sub
End Class

I am having "NullReferanceE xception was Unhandled" at this line "Dim Login = Me.ClientsTable Adapter1.Client Query(TextUsern ame.Text, TextPassword.Te xt)"