1. I have frame called MGMainFrame.

    and this is part of my addon

           screenWidth = GetScreenWidth()
           height = GetScreenHeight()
           GMMainFrame:SetSize(screenWidth, height)

    I want to add new Label in LUA as child this Frame(GMMainFrame) and i have no idea how to do this :/

    PS: frame is created in XML FRAME

    OK i find solution :D

    here it is.