You can use the key down events. The outputs from the event give you the information as to what key was pressed. You can then just run the same code that you run in the other event.
If you are trying to differentiate between return and enter you will need LabVIEW 8.0.
The only down side to the value change is that you may get more events than you want. For example I like to use tab and shift-tab to move around things. So if I was entering my password and realized I had made a mistake in my user name I may hit shift-tab to go back to the user name. In this case we get the value change, and depending on his code we hit ok and my login fails. As the user I was not ready to hit enter or ok yet.
Small use case but it may depend on your users or how the whole thing comes together.