Resolved: Test if application is open

How can I test whether or not an application is open?

tell application “Finder”
set theList to the name of every process
if “QuarkXpress” is not in theList then

end if
end tell

This might be more efficient since it looks for a specific process instead of messing with a list.

tell application "System Events" to ¬
	set is_running to exists process "QuarkXpress"

if is_running is false then ¬
	display dialog "QuarkXpress is not running"

– Rob