>I have encountered two errors though not harmful in my program:
> 1. When keys are entered too quickly in program execution "Program error - interrupted" appears. After choosing "ignore" it appears no harm.
> 2. One of the textbox in a grid is read-only. When something is entered by the keyboard "This object is read-only" appears.
>
> I wonder how to suppress the appearance of the above error messages in the screen.

The first one needs some extra background information (What keys? Entered into what? Textbox? Combobox? Spinner? Function keys, ESC key??)
Considering question no.2, put "RETURN .F." into When() Event of the textbox you want to be read-only, and you'll get rid of the "read-only" message.

Cheers.