>Hi,
> yes, it work!!!
> Thank you

The problem was the following line:

USE DBF("mycursor") AGAIN SHARED

Because you didn't specify a new workarea, VFP attempted to use the current one. The first step VFP takes in this situation is close any open cursor in that workarea before opening the new cursor. When it closed DBF("mycursor"), the disk presence went away and the subsequent USE failed.

As Sergey suggested, you needed to select a new workarea using SELECT 0. You could have specified the new workarea in the same command:

USE DBF("mycursor") AGAIN SHARED IN 0 ALIAS MYCURSOR1

The other problems you faced that Sergey's post addressed was the fact that you need to have unique names when opening a cursor for read/write. If you don't specify AGAIN, VFP thorws an error saying the file is in use. If you use AGAIN but keep the same alias name, VFP throws an error stating the alias has already been used.

Ex.
Select * from mytable into cursor tempcursor NOFILTER
Use dbf("tempcursor") AGAIN IN 0 ALIAS MyRealAlias