How do I make correct shadows..

Why are the shadows of my objects just boxes? I think the shadow should have the shape of the sprite.

All my Sprites were with alpha channels.

Sorry for my bad englisch! I hope someone could help me.

EDIT:

-attached screenshot

I would suggest adding a screenshot and perhaps a capx so people can give you better help.

Thanks for the quick answer! Here is the capx.

ok, I fixed it for you.

The shadow does not use alpha it uses the the sprites collision polygon. So when in the sprite editor you need click on the 'Set collision polygon' tool icon, then for each animation frame you need to right click on your sprite and select 'Guess polygon shape'

It works! Thank you very much.