用 try...except ,try...finally 呀
例:
try
RemoteServer.AppServer.SetDatabaseName(DatabaseName.Text, '');
except
on E: Exception do
if E.Message = 'Password Required' then
begin
if InputQuery(E.Message, 'Enter password', Password) then
RemoteServer.AppServer.SetDatabaseName(DatabaseName.Text, Password);
end else
raise;
end;