Why does this TCL proc with no args not work?

This should be an easy one for someone...

I had a function in a TCL script called unwrap. Modifying it, I realized I no longer needed to pass it args.

So I changed it to

unwrap {} {...}

Now when I call it with no args, i.e.:

unwrap

I get an error invalid command unwrap

Ideas? How do I properly format a TCL function with no args?

I tried to use this reference, which showed a call identical to mine:
http://users.belgacom.net/bruno.champagne/tcl.html

Is that page incorrect?

FYI, removing the inner code and inserting it into the spot of the call works, so I know its just my syntax, not the function code itself.

Thanks in advance!