{"identifier":10005,"topic":"","name":"Writing message handlers 2","text":"Of course, HyperCard doesn\u2019t know about the doubleBeep <\/code>command, so it will never be sent automatically in response to an event. But you can send doubleBeep <\/code>from the Message box or use it as a statement in other handlers.

\n\n For example, the script of a card button might contain the following handler for the system message mouseUp<\/code>:

\n\n 
on mouseUp\n  doubleBeep\nend mouseUp<\/pre><\/code> 
\n
\nIf the script also contains the doubleBeep <\/code>handler (or if the script of any object later in the message-passing path contains it), the mouseUp <\/code>message will send the doubleBeep <\/code>message, and doubleBeep <\/code>will send two beep <\/code>commands. Because beep <\/code>is a built-in command, HyperCard beeps twice. 

\n\n If HyperCard can\u2019t find the doubleBeep <\/code>message, it will complain (with a dialog box) that it \u201ccan\u2019t understand\u201d the message. 
\n","related":{"20813":null,"6658":"Handling messages","26982":"on","8578":"The message-passing order","10721":"Using parameter variables","5306":"What are messages?"},"examples":"","demo":"

\n\n ","debug":{"9":["Of course, HyperCard"],"10":["If the script also c"]}}