[AS] Set every character leading to auto

I can't seem to get this to do what I expect.

tell application "Adobe InDesign CS5.5"

tell every text frame of page 1 of active document

  set leading of properties of every character of every paragraph to auto

end tell

end tell

The script I am working on imports text. Everything works except the leading, it comes in with "0 pt" leading and I need the script to basically check every character on the page and if the leading is 0 set it to auto.... I put this together as a quick and dirty test to try and make it work and in no way represents the final code.

Everything I have tried has either done nothing or gives me an error saying "Expected number, string or auto" when I give it auto.

I don't care if it is AS or JS as long as it works.