Populate data in listbox in a form

Hi Friends,
How do I populate data in a listbox which is there in a form. And change the data once I change the tab.
Like I have names in different tabs named as A,B,C etc. Now there is a form where i have inserted a tabstrip and named as A,B,C etc.
What I want it the names are populated in the the Listbox depending on the tab I select, like if I select tab A in the form all the names in the sheet A is listed, when I select tab B in the form all the names in the sheet B is listed and so on.
Please note that the names are not final as I will add and delete later on so it will be great if the list get's automatically updated when I click the Button "Call List" in the "Mainsheet".Please help me.
best regards,
me.