local function init()
        --Create a group that contains the entire screen and tab bar
        mainView = display.newGroup()   
 
        --Create a group that contains the screens beneath the tab bar
        tabView = display.newGroup()    
        mainView:insert(tabView)
 
        
        if (not userID) then
            print ("user is 0")
            local path = system.pathForFile( "user.txt", system.DocumentsDirectory )
            -- io.open opens a file at path. returns nil if no file found
            local fh = io.open( path, "r" )
            if fh then
               -- read all contents of file into a string
                userID = fh:read( "*a" )
                --native.showAlert("test",userID,{"ja"},onComplete)
                fh:close()
            else
                local fw = io.open( path, "w" )  -- open/create for write
                fw:write("0")
                fw:close()
            end
            createTabs()
        else
            print ("user is not 0")
            createTabs()
        end
        return true
end
function createTabs()
    if (userID == "0") then
    tabBar = viewController.newTabBar{
             background = "gfx/tabBar.png",      --tab bar background
             tabs = {"Hem", "Regler"}, --names to appear under each tab icon
             onRelease = showScreen  --function to execute when pressed
     }
     mainView:insert(tabBar)
     loadScreen("screen1")
     tabBar.selected()
    else
        tabBar = viewController.newTabBar{
                     background = "gfx/tabBar.png",      --tab bar background
                     tabs = {"Hem", "Regler", "Rapportera", "Topplista"}, --names to appear under each tab icon
                     onRelease = showScreen  --function to execute when pressed
             }
        mainView:insert(tabBar)
        print ("tabbar loaded")            
        print ("user id " .. "" .. "is present so load screen 3 and set that as active tab")
        loadScreen("screen3")
        tabBar.selected()
 
    end
end