alpha problems

Ok so I have been fighting with alpha textures all day. I got some help from Niel and Aarku. They showed me how to make an Alpha layer in the chanels box in PS. Then I flatened my image to black. Problem is when I get it into unity insted of my alpha chanel being black and white its grey and black so my entire tree looks like a ghost. I have tryed it many times. I made sure that export alpha masks is on for the psd. What am I doing wrong? and could we maybe get an alpah shader where I just select one image for the texture and one for the alpha mask like all the 3D programs. Thanx Jeff

Got it working, had to do with the import greyscale as Alpha. I think the problem was that no alpha was coming in, so it seemed like I had to push that to get the alpha in. Then once I was realy getting a graphic with an alpha when I took that off it worked fine. Jeff