[Janom]

Код:

procedure TForm1.Button1Click(Sender: TObject);
var
  i:Cardinal;
begin
for i:=0 to Form1.ComponentCount-1 do
  begin
    if Form1.Components[i].ClassType = TEdit then
      if TEdit(Form1.Components[i]).Text<>'' then
        TEdit(Form1.Components[i]).Enabled:=False;
  end;
end;