PeekMessage( @cMsg, hWnd, nFiltFirst, nFiltLast, nRemove) -> lresult
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 PARAMETER:

   <cMsg>       This character var will contain a MSG structure after 
                the call with message information from the application's 
                message queue. It therefore must be passed by reference ( @ ) 

   <hwnd>       The handle of the window whose messages are to be examined. 
                PeekMessage retrieves only messages associated with the 
                window identified by hWnd, or any of its children, and 
                within the range of message values given by the nFiltFirst
                and nFiltLast parameters. 
                If hwnd is NULL, PeekMessage retrieves messages for any 
                window that belongs to the application making the call.

   <nFiltFirst> specifies the value of the first message in the range of 
                messages to be examined. If nFiltFirst and nFiltLast are 
                both zero, the filter is disabled and PeekMessage returns
                all available messages.
                The WM_KEYFIRST ( 100h ) and WM_KEYLAST ( 108h ) flags 
                can be used as filter values to retrieve all key messages; 
                the WM_MOUSEFIRST ( 200h ) and WM_MOUSELAST ( 209h ) flags
                can be used to retrieve all mouse messages. 

   <nFiltLast>  specifies the value of the last message in the range of 
                messages to be examined. 

   <nRemove>    Removal-Flags, which specify how messages are handled. 
                This parameter can be a combination of the following values 

                Value        Meaning

                PM_NOREMOVE  (0) Messages are not removed from the queue 
                             after processing by PeekMessage. 
                PM_NOYIELD   (1) Prevents the current task from halting and 
                             yielding system resources to another task. 
                PM_REMOVE    (2) Messages are removed from the queue after 
                             processing by PeekMessage.


 DESCRIPTION:

  The PeekMessage function checks the application's message queue for a 
  message and places the message (if any) in the specified cMSG structure. 

  PeekMessage does not remove messages from the queue. The messages remain 
  in there until processed. Unlike the GetMessage function, PeekMessage
  does not wait for a message to be placed in the queue before returning.
  PeekMessage yields control to other tasks, unless the PM_NOYIELD flag 
  is set. 
  However, if there is a WM_TIMER message pending, PeekMessage will yield 
  regardless of the PM_NOYIELD flag. 


 RETURNS:

  The return value is TRUE if a message is available, and FALSE if not.