Stnd Addition conflict with Quark 6

I’ve a got a simple script that copies the project name of a Quark document to the layout name, and I’m trying to truncate the file extension from that layout name.

the standard addition – offset of someString – lets me do this until I activate Quark. It looks as tho Quark has a “same name” class that interferes. Is there any way I can override the Quark class, and use the std addition instead? Outside the “tell” the code works fine. Obviously, I haven’t done any of this in a while. Code follows. I marked the problem lines with “–>”

Thanks in advance,
Christine

tell application “QuarkXPress”
activate

try
	-- This line will ensure that a document is open, before proceeding
	if not (exists document 1) then error "No document is open."
	set X to count every layout space of project 1
	repeat with i from 1 to X
		--set testText to "Testfile585460.qxp"
		set finalText to ""
		set testOffset to 0 as integer
		set testText to name of document 1
		set name of layout space i of project 1 to testText
		if testText ends with ".qxp" then
			set numberChar to count of testText

—>set testOffset to offset of “.qxp” in testText
display dialog "The offset of .qxp is " & testOffset
set newFilename to (characters 1 thru (testOffset - 1)) of testText
display dialog "The new filename is " & newFilename

		else if testText ends with ".qxd" then
			set numberChar to count of testText

—>set testOffset to offset of “.qxd” in testText
set newFilename to (characters 1 thru (testOffset - 1)) of testText
display dialog "The new filename is " & newFilename
end if

	end repeat
		end try

end tell

You can try:

tell me to set testOffset to offset of ".qxp" in testText

Or:

set testOffset to run script "«event sysooffs» given «class psof»:".qxp", «class psin»:"" & testText & """