The 'XDo' graphical user interface provides a collection of tools for 
organizing data and is built on top of the MIDAS package DO (Data Organizer).
Help files for each of the existing commands is accessible in MIDAS while
the chapter 17 of the manual (Vol.B) provides  general information about 
the tools.
 
This implementation of the software has been adapted for working on-line
at the NTT: Each time an image  is sent to the workstation by the acquisition
system, the information contained in the header of this file is stored into
the OST (Observation Summary Table) and displayed in the scrolled windows.

The OST is reset by the introducing astronomer at the beginning of each
EMMI/SUSI observing run.  The table is updated independently of this Graphical
User Interface having been started or not.

The images are automatically classified according to their exposure types and
their optical paths. 
The automatic association of scientific and calibration frames is not yet
implemented.

The user is provided with a set of NTT specific defaults for all major 
functions. They are listed in the help "On NTT defaults..."