Strobe effect with Avisynth

[eugenid]

I have a video. And I want after each frame put one black frame - like this :

Frame 1, Black Frame, Frame 2, Black Frame, Frame 3 ....

I find some easy way to do this by script.But I dont know how do this?
Please help...

[scharfis_brain]

a=avisource("video.avi")
b=a.blankclip()
interleave(a.selecteven,b.selectodd)

[eugenid]

This isnt exactly I want to...
But I do some corrections ...

a=avisource("video.avi")
b=a.blankclip()
interleave(a,b)

And that is it...
Anyway , Thanks