error in: local listener = function(event)

    local ui = require("ui")
    -------------------------------------------
    -- General event handler for fields
    -------------------------------------------
    -- You could also assign different handlers for each textfield
    local function fieldHandler( event )

        if ( "began" == event.phase ) then
            -- This is the "keyboard has appeared" event
            -- In some cases you may want to adjust the interface when the keyboard appears.

        elseif ( "ended" == event.phase ) then
            -- This event is called when the user stops editing a field: for example, when they touch a different field

        elseif ( "submitted" == event.phase ) then
            -- This event occurs when the user presses the "return" key (if available) on the onscreen keyboard
        -- Hide keyboard
            native.setKeyboardFocus( nil )
        end
    end
    -- Predefine local objects for use later
    local defaultField
    local fields = display.newGroup()

    local isAndroid = "Android" == system.getInfo("platformName")
    local inputFontSize = 18
    local inputFontHeight = 30
    if isAndroid then
        -- Android text fields have more chrome. It's either make them bigger, or make the font smaller.
        -- We'll do both
        inputFontSize = 14
        inputFontHeight = 42
    end
    defaultField = native.newTextField( 10, 80, 300, 30, fieldHandler )
    defaultField.font = native.newFont( native.systemFontBold, inputFontSize )
    defaultField.align = "center"
    -- Add fields to our new group
    fields:insert(defaultField)
    local bkgd = display.newRect( 0, 0, display.contentWidth, display.contentHeight )
    bkgd:setFillColor( 0, 0, 0, 0 )

    local listener = function( event )
        -- Hide keyboard
        print("tap pressed")
        native.setKeyboardFocus( nil )
        bkgd:removeEventListener("tap", listener)   ----------< This is line 196
        bkgd:removeSelf()
        verifyName(defaultField)
    end


----------Error Produced----------------


ERROR: nil key supplied for property lookup.
stack traceback:
    [C]: ?
    [C]: ?
    ?: in function 'removeEventListener'
    /Users/eric/Documents/CRPG/scene_intro.lua:196: in function </Users/eric/Documents/CRPG/scene_intro.lua:192>
    ?: in function <?:215>
tap pressed
Runtime error
    ERROR: nil key supplied for property lookup.
stack traceback:
    [C]: ?
    [C]: ?
    ?: in function 'removeEventListener'
    /Users/eric/Documents/CRPG/scene_intro.lua:196: in function </Users/eric/Documents/CRPG/scene_intro.lua:192>
    ?: in function <?:215>