Forms Data Controls :: Datacontrol Pass From Masterpage To Child Page?

I have a masterpage and 1 childpage. In master page there is a listbox to present a data when a child page button is clicked. Listbox name is x1 for example.

When i am in childpage's button click event: i do not see that x1 named listbox due to namespace i guess.

For example masterpage name is masterpage1. When we are in childpage in button click event.

To try masterpage1 objecttemp = new masterpage1()

button1_Click() (child pages button click event)

masterpage.x1.items.add("button 1 clicked"); it is not being able to reachable too.

Also i encountered another issue related to that. When in masterpage for example masterpages click event. (its a login panel and when user clicks login, i had wanted to add a text information to listbox). In child pages when user clicks to login button which belongs masterpage top panel. It does not seem like working. It may be related to asp page master child life cycle and i do not know good. I wanted to able to add a string to listbox that belongs and come from masterpage in child page. Is there any way to use a datacontrol in childpage that belongs to masterpage.