Refresh a combobox in a parent tabpage after making an entry in child tabpage

[wire_jp]

Hello,

I am using MySQL Database which is connected to Visual Studio Community 2017 Community Edition software. I have used a TabControl form, with tables in each TabPage. I am trying to refresh a combobox on the parent TabPage, after making a data entry in a textbox in the child TabPage. The child form has two textboxes: "txtBookID" and "txtBookName". The textbook "txtBookID" is autoincremented. The Parent form has a combobox called "CboBookID_fkey". If I make a new entry in the textbook "txtBookName", I would like the CboBookID_fkey, to update with the new SelectedItem. However, when I make an update in the textbox on the child TabPage, the "CboBookID_fkey" combobox do not automatically update with the changes. My vb.net code is shown below: -

Imports MySql
Imports MySql.Data.MySqlClient
Imports System.Configuration
Imports MySql.Data

Public Class Form1
    Inherits Form
Dim conString As String = "Server=localhost;Port=3306;Database=mydatabase;userid=root;password=password;persist security info=True"	
    Dim con As MySqlConnection = New MySqlConnection(conString)

Private Sub SelectBookName(cb As ComboBox)

        Dim con As New MySqlConnection(conString)

        Dim myCommand As MySqlCommand = connection.CreateCommand()
        myCommand.CommandText = "SELECT BookName from Books"
        con.Open()

        Dim reader As MySqlDataReader

        reader = myCommand.ExecuteReader()
        While reader.Read()
            cb.Items.Add(reader.GetString("BookName"))
        End While


        con.Close()

    End Sub

    Private Sub TabPage2_Click(sender As Object, e As EventArgs) Handles TabPage2.Click
        InitializeComponent()
        CboBookID_fkey.Items.Clear()
        SelectBookName(CboBookID_fkey)
    End Sub

End Class