TAdoConnection Disconnect

Hi,
(Delhi 7, Sql Server 2000)

I have a TAdoConnection and I open this connection with starting program
(ADOConnection1.Open).
After a button click I want to close connection (after this time user can
"detach"/"take offline" database):

-------------------------------------------
procedure TForm1.CloseConnectionClick(Sender: TObject);
begin
ADOConnection1.Close;
end;
-------------------------------------------

After click this button click *connection doesn't closed*
I can use ADOConnection1.Execute(...) method without any error and I can't
"detach"/"take offline" database in Sql server enterprise manager because of
connection.

How can I disconnect db?


.