display.NewRect() ?

I need borders that are the screen width and height of the droid since im working with that. The following below doesnt make a floor at the bottom of the screen in landscape mode. I don’t want the floor showing.
What are the right locations for the floor? What about the right and left walls?
[lua]local floor = display.newRect(0, 479, 320, 1 )
floor:setReferencePoint(display.CenterReferencePoint)
floor.x = _W/2; floor.y =450; [import]uid: 54001 topic_id: 9560 reply_id: 309560[/import]

This will make four border rectangles around the screen.

rect1 = display.newRect(1, 320, -1, 0) rect2 = display.newRect(480, 1, 0, 481) rect3 = display.newRect(1, 320, 321, 0) rect4 = display.newRect(480, 1, 0, -1) [import]uid: 22824 topic_id: 9560 reply_id: 34923[/import]