Layers adjustment

I am trying to figure out how to make an adjustment to a specific Photoshop layer (in this case a tweaking the color on a person extracted from the background by green screen) without affecting the other layers. I have tried Adobe help but can't seem to find the solution.

I would appreciate any help. I am using Photoshop CS4.

Thanks,
Tom

If you are in the layer you want to adjust click on Ctrl M and you will get curves window to work with. If you use create new fill or adj layer then curves will affect entire picture.

Put them (the original layer and the adjustment layer on top of it) in a group and set the group to normal, or ctrl-alt-g the adjustment layer to make it clip to the layer below (layer menu > create clipping mask).

IN CS3 you hover on the line between layers (the cursor changes to intersecting circles) and click alt