File status (see the table below) or empty string if an error occurred. To get the error number, use MCIErr. To get more details on the error, use MCIMsgErr or ErrorInfo with the errMessage constant.
The status report of the command is returned by MCIRetrieve.

MciStatusNotReady	Drive not ready (no CD in the drive for example)
MciStatusOpen	File opened only.
MciStatusParked	The player is parked: the player heads parked.
MciStatusPause	The file is paused
MciStatusPlay	The file is opened and it is currently played
MciStatusRecord	The file is currently recorded
MciStatusSeek	Find/seek in progress in the file
MciStatusStop	The file is stopped

Name of the media file to be used (AVI, MP3, etc.) or alias defined when opening the file (MCIOpen).

Additional parameters if necessary. These parameters can be known by checking the documentation of the Windows MCI function named "status".
The MciWait constant can be added to this string. This constant is used to indicate that the program must wait for the end of the MCI command to run the rest of application.

Name of the window used to intercept and manage the different messages sent by MMSYSTEM.DLL. These messages are in MM_xxxxxx format and can be retrieved with Event. You can for example get messages regarding the management of the CD ROM or Joystick.