question regarding dynamic control event handler

Folks here is a background of what am trying to do
display a user with a list of companies in a list box, when the user selects a company list out the locations of the company, and when the user selects the location then display a message I like to work for <<company>> at the location <<location>>. I want to acheive this using creating dynamic controls.
Here is what I did so far
    void Page_Init()
    {
        //create a list box with company names and based upon selection populate the location combo.
        ListBox lbox = new ListBox();
        lbox.ID = "lbox";
        lbox.Items.Add("Microsoft");
        lbox.Items.Add("Google");< ...