How do I repeat my background?

while preventing to be white background itself?

I'm sorry, but I don't understand the question..

Could you try explaining what you want in a better way?

when my background scroll down, it becomes white background after my whole background and then back to 0 y-coordinate and repeat its process while I want a repeating my own background to scroll down.

Watch this tutorial <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile">

If I'm not mistaken, it sounds like you want the background to be continuous as you scroll downward. If this is the case then I'd start by making sure that the background image/sprite has the same height as the layout.

If this is not what you want, please give us some more details. If possible, some screenshots of the layout would be nice too.

Try these steps:

1. Put your background picture in as tiled background, not sprite.

2. Change it's origin point to 0,0 and then move it to position 0,0.

3. Resize it so that it's y(if you want height) is twice the size of your layout.

4. Add a bullet behavior to it.(speed= whatever you want, acceleration=0, gravity=0, bounce of solids=no, set angle=no, initial state=enabled)

5. Add event: on start of layout>tiled background-set bullet angle of motion to xx degrees(90 degrees if you want it to go down or 270 if you want it to go up)

6. Add another event: tiled background- y is less or equal to Self.Height / 2 action: tiled backround set y to Self.Y + Self.Height / 2

that's I use with my layout but white background still showed up vikings. anyways, thanks guys,. I will try later the millet's reco.