VDisplayDialogMessage - displays a message in the dialog window.
  char *msg;
  VDisplayDialogMessage displays a message in the dialog window.
VDisplayDialogMessage checks whether the dialog window is in front of the
image window or not. If it is, VDisplayDialogMessage displays the message in
the dialog window, else it stores it in a pixmap. The area reserved for
the dialog message is two lines. VDisplayDialogMessage computes the maximum
number of characters allowed per line depending on whether the panel
is on or off. If the message is too long for one line, VDisplayDialogMessage
places the rest of the message into the second line automatically. If the
message cannot be accomodated in the message area, VDisplayDialogMessage
truncates the message and returns an error code.
Return Value
  0 - work successfully.
  1 - memory allocation error.
  224 - message displayed is out of window boundary.
  258 - pixmap of the dialog window is NULL and image window is in 
        front of the dialog window.
  msg - specifies a string of message to be displayed in the dialog window.
Side Effects
Entry Conditions
  If msg is NULL, or VCreateColormap is not called earlier,
VDisplayDialogMessage prints an error message to the standard error stream,
produces a core dump file and exits from the current process.
Related Functions
VDisplayImageMessage, VDisplayButtonAction, VDisplayErrorMessage.