webform copy

While I'm doing my webform entries, I'd like to have a "copy" function that allows me to make a webform that slightly modifies another existing webform. As an example, take a contact form that requires a user to enter his operating system and a contact form that doesn't. Both forms are pretty similiar. They only need a different description and one has a textfield that the other doesn't have. If it was possible to copy one webform and take it as a base for another webform, this would simplify things a bit.