Yes! Thanks Denis - this worked! I tried the previous suggestions; I
re-edited the file of *.txt to no avail, and also the other one
(comets.dat) but neither worked. I wonder why the others didn't work!

Thanks to all.

Lawrence

>Lawrence,
>
>I am not sure if you did the right procedure.
>
>First try, under menu goto 'asteroid' enter '2003 UB313'.
>
>Second, if the object does not exist,
>
>get MPC : http://cfa-www.harvard.edu/mpec/K05/K05O41.html
>Right click on the screen and 'save page as...' in a directory.
>
>then you have to go to 'extra', 'add MPC comet/asteroid', at the bottom
>'add asteroids/comets'. Find the MPC file saved above and select. Repeat
>the first line above.
>
>
>Denis