tabcontrol.Initialize("TabControl")
        nav1.Initialize("nav1")
        nav2.Initialize("nav2")
        nav3.Initialize("nav3")
        nav4.Initialize("nav4")
        tabcontrol.Pages = Array(nav1,nav2,nav3,nav4)
        nav1.ShowPage(pageHome)
        nav2.ShowPage(PageMyorder)
        nav3.ShowPage(pageCredit)
        nav4.ShowPage(pageSelf)
pageHome.TabBarItem=tbi   
    PageMyorder.TabBarItem=tbi2
    pageCredit.TabBarItem=tbi4
    pageSelf.TabBarItem=tbi5   
    Main.App.KeyController = tabcontrol
    tabcontrol.SelectedIndex=index