Sexing red-eyed tree frogs?

["Red-eye"_Matt]

Does anybody have any ideas as to how you would sex a red-eye? I have read that you can tell the male from a female by the shape of the nose. The book said that a male's nose is sloped from nostril to the upper lip while a females is convex in shape. I tried using this method on ours but it seems to hard to tell like this as the area is really small and as these are our first neither one of us has any real experience with them.

Any ways that you guys know of would be appreciated.

Matt