HP Compaq t5710 Thin Client - Manual (Page 220)

15-6
Initialization Commands
Disable 'Exit' Message Box
Registry Entry: WarnExit = "off"
Command Line: -J
Default Setting: Enabled
A message box will be displayed if you attempt to exit the emulator while a network
session is still active. These commands will disable the message box so that the
emulator automatically closes the network connection when it is exited.