UI fields not updating with new values.

Code:
fiveminqq={ }



-- module settings

fiveminqq.mainwindow = { name="5minqq", x=550, y=100, w=200, h=280 }

fiveminqq.tickRate = 2000



-- init & ui

function fiveminqq.ModuleInit()

    GUI_NewWindow(fiveminqq.mainwindow.name,fiveminqq.mainwindow.x,fiveminqq.mainwindow.y,fiveminqq.mainwindow.w,fiveminqq.mainwindow.h)



    GUI_NewField(fiveminqq.mainwindow.name,"Target:","fiTargetName")    

end



-- main loop

fiveminqq.lastTick = 0

fiveminqq.lastKnownTarget = ""



function fiveminqq.OnUpdateHandler( Event, ticks )



    if (ticks - fiveminqq.lastTick > fiveminqq.tickRate) then

        fiveminqq.lasttick = ticks



        -- monitior target

        local mytarget = Player:GetTarget()

        if(mytarget) then

            if(mytarget.name ~= fiveminqq.lastKnownTarget) then

                d("[Last known target: " .. fiveminqq.lastKnownTarget .. "] [New target: " .. mytarget.name .. "]")

                fiveminqq.lastKnownTarget = mytarget.name;

                fiTargetName = mytarget.name; -- why does this not update the gui field???

            end

        end



    end

end



-- subscriptions

RegisterEventHandler("Module.Initalize",fiveminqq.ModuleInit)

RegisterEventHandler("Gameloop.Update",fiveminqq.OnUpdateHandler)