ANSWER: This is not permissible.

He can ask the imam or the admins of the masjid whether anyone has brought forward missing items or not but not to announce this in the masjid.

QUESTION: Ya sheikh people in the masjid sometimes lose their keys .and it would be somewhere in the masjid .so the person who lost it requests the imam to announce in the masjid to handover the key to him .and this is done after salah.is this permissable and how should one find the keys if he lose it in the masjid