>I have a grid on a view.
>When the user press a + key somewhere, I want to insert the new record just after the current one, not at the end.
>I thought about using an index but when I am using INDEX ON order TAG order, it tells me "command cannot be issued on a table with cursor in table buffering mode".
>What is the "usual way" to do this.
>

An index is the only way to do it. You didn't say if the grid was based on a table or a view. If a view, and you just need to set buffering to table (I think you have the error message backward: you can't index a view with ROW buffering enabled).

CURSORSETPROP("Buffering",5,"MyView")
INDEX ON someField TAG SomeField

then, when the user presses the "+" key, give the new record a value just greater than the one they are sitting on for the field you have indexed and set order to.