Alpha Channel in gimp?

How do i enter the alpha channel of a skin in GIMP?

Make the background transparent.

You obviously don’t know anything about skinning, problem solved btw

Sorry I read it wrong I thought you were asking how to add an alpha channel :S

So how do you enter an alpha channel in GIMP (as it would be useful to know).

And no I don’t know that much about skinning I only started doing stuff for GMod 2 weeks ago (at least I think it was, i’m not that good at keeping track of time recently).