To add fields to table does not work
I am working in this database which I didn't create, but I added a tab in the lay-out to work with. I added my fields and they are shown in the lay-out. Now I have this problem with adding those same fields to the table.. when I click Modify and select the fields I want to add, nothing happens. And there was this + sign on the right side of the table but it disappeared.. There are already lots of fields in this table, which is the work of someone else.
How do I change the table so that it shows my fields?