Private Sub btnComp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnComp.Click
        Dim lngfact As Long = 1

        Dim intnum As Integer
        intnum = Val(Me.txtNum.Text)
        Dim intcount As Integer
        For intcount = 1 To intnum
            lngfact = lngfact * intcount
        Next intcount

        Me.lblmessage.Text = "Factorial is:"
        Me.lblfac.Text = lngfact
    End Sub

    Private Sub txtNum_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtNum.TextChanged
        Me.lblmessage.Text = Nothing
        Me.lblfac.Text = Nothing
    End Sub