Visual Basic.NET - Visual Studio 2015 - validar la hora seleccionada por el usuario

' instruccion para validar la hora seleccionada

Dim validacion As String

validacion = ComboBox2.Text

If validacion <= Hora.Text Then

    ComboBox2.Text = ""

    TextBox4.Text = ""

    MsgBox("Sorteo culminado, seleccione una hora posterior", vbCritical)

    ComboBox2.Focus()

    ' fin validacion de hora seleccionada

End If

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

    Hora.Text = Now.ToLongTimeString()

End Sub

Private Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click

    Dim valhora As String

    Dim horasist As String

    horasist = Hora.Text (el valor de Hora.text viene de un control timer para tomar la hora de windows)

    valhora = ComboBox2.SelectedValue

    If valhora = horasist Or valhora < horasist Then

        MsgBox("Sorteo culminado, selecciono otra hora", vbCritical)

        ComboBox2.Focus()

    Else

        ' agrega los valores al DataGridview1 

        DataGridView1.Rows.Add(TextBox2.Text, ComboBox1.SelectedValue, ComboBox2.SelectedValue, TextBox3.Text, TextBox6.Text)

        ' suma la columna apuesta

        Dim Total As Single

        Dim suma As Integer = DataGridView1.CurrentCell.ColumnIndex

        For Each row As DataGridViewRow In DataGridView1.Rows

            Total += Val(row.Cells("suma").Value)

        Next

        TextBox6.Text = Total.ToString

        'fin instruccion valores y suma columna apuesta

        TextBox2.Text = ""

        ComboBox1.Text = ""

        ComboBox2.Text = ""

        TextBox3.Text = ""

    End If

End Sub

Private Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click

    If ComboBox1.SelectedValue = "Loto Activo" Then

        Dim valhora As String

        Dim horasist As String

        horasist = Hora.Text

        valhora = ComboBox2.SelectedValue

        If valhora = horasist Or valhora < horasist Then

            MsgBox("Sorteo culminado, seleccione otra hora", vbCritical)

            ComboBox2.Focus()

        Else

            If Val(TextBox3.Text) >= 500 Then

                Dim items As New ListViewItem(TextBox2.Text$)

                items.SubItems.Add(ComboBox1.SelectedValue)

                items.SubItems.Add(ComboBox2.SelectedValue)

                items.SubItems.Add(TextBox3.Text$)

                items.SubItems.Add(TextBox6.Text$)

                ListView1.Items.Add(items)

                ' sumas totales

                TextBox6.Text = Sumar()

                'fin sumas

                'vacia info

                TextBox2.Clear()

                ComboBox1.SelectedValue = 0

                ComboBox2.SelectedValue = 0

                ComboBox3.SelectedValue = 0

                ComboBox1.Enabled = False

                ComboBox2.Enabled = False

                TextBox3.Clear()

                TextBox3.Enabled = False

                TextBox1.Focus()

                Button3.Enabled = True

            Else

                MsgBox("Apuesta minima 500 Bs.", vbExclamation)

            End If

        End If

    End If

Nota: de aqui hacia arriba funciona bien, el codigo de funciona igual al selecciona La Granjita arroja error en combobox3

    If ComboBox1.SelectedValue = "La Granjita" Then

        Dim valhora As String

        Dim horasist As String

        horasist = Hora.Text

        valhora = ComboBox3.SelectedValue

        If valhora = horasist Or valhora < horasist Then

            MsgBox("Sorteo culminado, seleccione otra hora", vbCritical)

            ComboBox2.Focus()

        Else

            If Val(TextBox3.Text) >= 500 Then

                Dim items As New ListViewItem(TextBox2.Text$)

                items.SubItems.Add(ComboBox1.SelectedValue)

                items.SubItems.Add(ComboBox3.SelectedValue)

                items.SubItems.Add(TextBox3.Text$)

                items.SubItems.Add(TextBox6.Text$)

                ListView1.Items.Add(items)

                ' sumas totales

                TextBox6.Text = Sumar()

                'fin sumas

                'vacia info

                TextBox2.Clear()

                ComboBox1.SelectedValue = 0

                ComboBox2.SelectedValue = 0

                ComboBox3.SelectedValue = 0

                ComboBox1.Enabled = False

                ComboBox3.Enabled = False

                TextBox3.Clear()

                TextBox3.Enabled = False

                TextBox1.Focus()

                Button3.Enabled = True

            Else

                MsgBox("Apuesta minima 500 Bs.", vbExclamation)

            End If

        End If

    End If

End Sub

valhora  = combobox3.text