Slide in pop ups

I am dipping my toe into affiliate marketing as we speak. I have just finnished designing my landing page, but now I need a way of building my lists.
I am looking for a script that produces these slide in pop ups, so my crucial opt in form is not blocked by the pop up blocker I thought were brilliant before i came across this problem.

I am sure there must be a free script out there. I checked hot scripts but the not being blocked thing is fairly important, and none of them gave that guarentee! Any one here have experience of such a thing!

Do it with a simple CSS layer instead of a slide in.