How to display Textbox from MySql when choosing Combobox

[Belajar]

I want to ask how to make when we press the value for the combo box. For other textbox can easily appear. So, the user can do input 2 times. Here I attach my code

   Private Sub combo1()
        conn.Open()
        Dim stringsql As New MySqlCommand("select * from supplier", conn)
        Dim dr As MySqlDataReader = stringsql.ExecuteReader
        ComboBox1.Items.Clear()
        While dr.Read()
            ComboBox1.Items.Add(dr("npwp"))
        End While
        conn.Close()
        ComboBox1.Items.Insert(0, "")
    End Sub
    Private Sub Utama_Load(sender As Object, e As EventArgs) Handles Me.Load
        combo1()

End Sub

[rproffitt]

I read your post multiple times and it's unclear what you are asking for. Also, what do you mean by "easily appear"?

I see the combo box which is "A combo box is a commonly used graphical user interface widget (or control). Traditionally, it is a combination of a drop-down list or list box and a single-line editable textbox, allowing the user to either type a value directly or select a value from the list."

Given the rather poor description of what you want to happen, I would be guessing badly. Try again but itemize your sequence of events and expected presentations and results.

Example:

1. A combo box is on a form populated from a source.
2. The user selects a value on the combo box.
3. ON CHANGE of the combo box value present a dialog box with entry boxes for what? I can't tell here.
4. What happens next?