[whpalmer4]

And better yet would be cleaning it up like this:

property doneDocName : "Done.oo3"

tell application "OmniOutliner Professional"
	
	-- format today's date in an appropriate way
	set today to current date
	set dateString to month of today & " " & day of today & ", " & year of today as string
	
	set original to front document of application "OmniOutliner Professional"
	
	-- open Documents/Done.oo3 if it exists and set path, if not, create it
	set doneDocPath to ((path to documents folder as string) & doneDocName)
	try
		open file doneDocPath
		set doneDoc to document named doneDocName
	on error
		set doneDoc to make new document at beginning of documents

A word of warning: this script won't copy over the structure of your completed stuff exactly, as nested items will only have the completed leaves copied, and then subsequent runs will capture the parents but not retain the structure, as seen in the before/after images attached.