🚀 go-pugleaf

I have a script that removes the contents of labeled text boxes on the
page:

tell application "InDesign 2.0.2"
		set myTextItems to all page items of active document
		repeat with aFrame in myTextItems
				copy aFrame to theFrame
				-- check only text frames
		if the class of theFrame is equal to text frame then
						-- see if the frame is on the page, not on the pasteboard
			repeat until {page, spread} contains the class of theFrame
				set theFrame to the parent of theFrame
			end repeat
						-- it is on the page, clear it
			if the class of theFrame = page and label of aFrame is "text_copy"
then
				set text contents of aFrame to ""
			end if
					end if
			end repeat
end tell

What I want is a script that does the same thing but to a series of
selected grouped items.
I tried changing 
		set myTextItems to all page items of active document          to
		set myTextItems to all page items of selection

but it would only work if I had only one grouped item selected and it
would do nothing if I had selected 2 or more grouped items.

I am new to applescript and completely lost.