Trouble in resizing the window

[rinklea]

This is my code:
function love.load()
love.graphics.setDefaultFilter('nearest','nearest')
love.window.setTitle('FLAPPY BIRD')

push:setupScreen(virtual_width,virtual_height,window_width,window_height,{
	resizable=true,
	fullscreen=false,
	vsync=true,
	
})

end

function love:resize(w,h)
push:resize(w,h)
end

But I still keep getting the error:
Error

push.lua:270: attempt to perform arithmetic on local 'h' (a nil value)

Traceback

push.lua:270: in function 'resize'
main.lua:25: in function main.lua:24
[C]: in function 'xpcall'

Please somebody help