Create new client folder with subfolders good for prepress

Useful script for prepress below, One enhancement im after is to have an error message or something when inputing client name and characters are more than 16.

property subf_names : {"LB Artwork", "Supplied Artwork", "PDF Proofs", "Fonts", "Print Files"}
property subfff_names : {"_Col T", "_Inca", "_Vutek", "_CutV", "_HP Gr", "_Chief"} -- change these folder names relevent to your work

--
display dialog "Enter Client name:" default answer "Client name (max of 16 characters)"
set j_name to text returned of result
repeat
	display dialog "Enter job number:" default answer "AA0000"
	set j_number to text returned of result
	exit repeat
end repeat
set job_number to text -9 thru -1 of ("0000" & j_number & "_") -- change 9 higher or lower for amount of characters
set temp_name to job_number & j_name
tell application "Finder"
	set main_folder to (make new folder at "Macintosh HD:Users:trigger:Desktop:JW WORK new" with properties {name:temp_name}) as alias
	repeat with this_name in subf_names
		set temp_name to this_name
		set subFolder to make new folder at main_folder with properties {name:temp_name} --> line changed: the last folder in the list must be "Print Files"
	end repeat
	
	repeat with this_name in subfff_names
		set temp_name to job_number & j_name & this_name
		make new folder at subFolder with properties {name:temp_name} -- line changed
	end repeat
	open "Macintosh HD:Users:trigger:Desktop:JW WORK new" -- change this to main folder to bring new folder to front
	set current view of Finder window 1 to list view
	set position of Finder window 1 to {200, 200}
	
end tell

Something like this:

set D1 to "Client Name (max of 16 characters)"
set D2 to "Client Name must be fewer than 16 characters, including spaces!"
set D to D1
repeat
	set j_name to text returned of (display dialog D default answer "Client Name")
	if (count j_name) > 16 then
		set D to D2
	else
		exit repeat
	end if
end repeat

Cheers, perfect thanks
JW