How can I import an image sequence into blender So I have a video and a image sequence  that I want to stick together using alpha over nodes.
My background is a .avi video, and I want to put a image sequence with alpha
transparency over it.

 

I use a image node and import all my png's.



and set the node to image sequence.



But when I move up and down my time-line the images don't change.
What should I do?
The Frames value in your Image Sequence node is set to 1, so it will only show the first frame of the sequence. Set that value to the total number of frames in that image sequence and you should see it update. You may also want to enable Auto-Refresh so you can see updates as you scrub.

That said, if you're just doing an Alpha-over, it would probably be way more suitable to do this in the VSE.