Cocoa dialog with progress bar controllable by AppleScript
tell application "ProgressDialog"
set name of window 1 to "example"
set message of window 1 to "Processing..."
set indeterminate of window 1 to true
end tell
delay 3
tell application "ProgressDialog"
set indeterminate of window 1 to false
end tell
set i to 3
repeat 8 times
tell application "ProgressDialog"
set message of window 1 to ("Processing... " & (i * 10) & "%")
set percent of window 1 to (i * 10)
end tell
delay 1
set i to (i + 1)
end repeat
tell application "ProgressDialog"
quit
end tell