Filling list boxes in .NET code

[Migrated content. Thread originally posted on 11 May 2012]

The following code doesn't seem to display my listbox contents after performing it. What am I missing?

method-id LBox_Button_Click final private.
local-storage section.
01 my-listbox type System.Windows.Forms.ListBox.
01 companyName type String.
procedure division using by value sender as object e as type System.EventArgs.

set my-listbox to new System.Windows.Forms.ListBox
invoke my-listbox::BeginUpdate

move "Fred" to companyName
invoke my-listbox::Items::Add(companyName)

invoke my-listbox::EndUpdate

end method.