Scratch Mask

Hi people, I am wondering if someone can help me. I have followed heaps of links and posts about creating a scratchie card effect however none of them are sufficient.

I need this to work in flash version 8, AS2 however the ones I have found are all AS1.

I just need to be able to have multiple scratch panels, each with a different letter underneath. A user will be able to scratch the top level off to revel whats underneath.

Please help…thanks