Parallax Effect, background not visible

Heres some code snippets from a simple game I made with a stationary 'ship' that fires bullets upwards from the bottom of the screen.

I'm sure you could modify it to fit your needs.

Type bullet
	Field image
	Field bulletx#
	Field bullety#
	Field xangle#
	Field yangle#
End Type

bulletimage = LoadImage("bullet.png")
MidHandle bulletimage

	shoot = KeyDown(57)		;space

	If shoot And MilliSecs() > lastshot
		thisBullet.bullet = New bullet
		thisBullet\image = CopyImage(bulletimage)
		RotateImage thisBullet\image, rotation
		thisBullet\bulletx# = 400
		thisBullet\bullety# = 550
		thisBullet\xangle# = Sin(rotation)
		thisBullet\yangle# = -(Cos(rotation))
		lastshot = MilliSecs() + 1000
	EndIf
		
	;bullet advance
	For thisBullet.bullet = Each bullet
		thisBullet\bulletx# = thisBullet\bulletx# + thisBullet\xangle# * 5
		thisBullet\bullety# = thisBullet\bullety# + thisBullet\yangle# * 5
		If thisBullet\bulletx# < -40 Or thisBullet\bulletx# > 840 Or thisBullet\bullety# < -40
			FreeImage thisBullet\image
			Delete thisBullet
		EndIf
	Next

	;draw bullets
	For thisBullet.bullet = Each bullet
		DrawImage thisBullet\image, thisBullet\bulletx#, thisBullet\bullety#
		If ImagesCollide(thisBullet\image, thisBullet\bulletx#, thisBullet\bullety#, 0, enemy, (enemyx-1)*40, (enemyy-1)*40, 0)
			KillEnemy(enemy)
		EndIf
	Next

The rotation variable in this code:

RotateImage thisBullet\image, rotation

is equal to the 'ships' rotation.

Set the bullets starting x,y values here:

thisBullet\bulletx# = 400
thisBullet\bullety# = 550

equal to the 'ships' location in your game.