Title: Prevent the TEdit component from beeping when invalid
Question: How can I prevent the TEdit component from beeping when invalid
keystrokes are entered?
Answer:
Trap the KeyPress event for the keys you do not want, and set the
key to #0 to prevent the beep.
Example:
procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if ((UpCase(Key) (UpCase(Key) 'Z')) then
Key := #0;
end;