How to set conditional default for an input clip ?

Quick question. Say I am writing a function with two-clip input - clp1 and clp2. If clp2 is not defined by the user, I want the function to default to clp1. Tried clp2 = default(clp2, clp1), but that gets rejected. What is the correct way to set this?

I guess I was considering the equivalent of: Code:

Strange, once again, Stephen R Savage's reply to my query, which was very helpful, was there one minute and gone the next. Kind of looks like I already knew the answer to the question I asked. I know people have commented on this before, but if someone deletes a post, it would be helpful to at least leave some indication that there was a post there, even if the reason for deleting is not given and/or the user's name is not stated. There are lots of things I have posted that I cringe to look at now, but my feeling is 'what I have written I have written'; if people post they should commit to it. Correct stuff sure, as an edit, but don't make other people look foolish. And in this case, I cant imagine why the user deleted his post, as it was very helpful.

@Stephen R. Savage, Your PM is turned off. Is there a reason why you delete half of your posts? (I restored your post in this thread for readability reasons.)

Thanks Wilbert.