h6. [[WindowManager]] h6(. » [[WindowManager SWI Calls|SWI Calls]] h6((. » [[Wimp_Poll|Wimp_Poll]] h6(((. » [[Reason Codes|Reason Codes]] h6((((. » User_Message_Recorded h2. User_Message_Recorded h5. (Reason Code 18) |_<. Exit | | |<^. Block | | |>^. +0|Length of block | |>^. +4|Task handle of sender | |>^. +8|My ref (senders reference number for this message) | |>^. +12| Your ref (senders reference number for a previous message, if this a reply, otherwise 0) | |>^. +16|[[Message Codes|Message Code]] | |>^. +20|… data… | h4. Use This code is returned from [[Wimp_Poll|Wimp_Poll]] and indicates that another task has broadcast a message to any of the following: # this specific task # a specific window belonging to this task # to all tasks h4. Notes The message code determines the meaning of the message sent. Unlike [[User_Message|User_Messages]], tasks that send this type of message can accept an acknowledgement message that the message was received. A task can acknowledge the message by calling [[Wimp_SendMessage|Wimp_SendMessage]] with the event code of 19 ([[User_Message_Acknowledge|User_Message_Acknowledge]]). Your_ref should be set to the original code sent (my_ref). This will prevent the sender from receiving its original message back from the Wimp with event code 19. Another method of acknowledging a message is to send a reply message using event code [[User_Message|User_Messages]] or [[User_Message_Acknowledge|User_Message_Acknowledge]] again with your_ref parameter set to the original message's my_ref. Both types of acknowledgement must take place before the next call to Wimp_Poll. A task that does not understand a message code should simply ignore it. Tasks should not respond to messages for no reason. h4. See also * [[Message Codes|Message Codes]] * [[Reason Codes|Reason Codes]] * [[User_Message|User_Message]] * [[User_Message_Acknowledge|User_Message_Acknowledge]] * [[Wimp_Poll|Wimp_Poll]]