Completing the rows in Salah

Q: We are working at the Biljurashi Passport Department, and we are located near a Masjid (mosque) which consists of two floors. There is a door in the place of our Department which we use to enter to the second floor of the Masjid. We offer Salah (Prayer) behind the Imam while being in the second floor of the Masjid although the first floor is so wide that there will be only one or two rows with the Imam on the first floor, and we form one or two rows on the second floor. We can see the Imam and those who offer Salah behind him from the gallery of the second floor of the Masjid.Our question is: Is Salah in such a case valid or are we required to (Part No. 6; Page No. 238

A: You should go down to the first floor to complete the rows and abide by the command of Allah's Messenger (peace be upon him), as related in the Hadith in which he (peace be upon him) said: Complete the rows, for I see you from behind my back. Moreover, it was authentically reported on the authority of Anas (may Allah be pleased with him) that Allah's Messenger (peace be upon him) said: Straighten your rows as the straightening of rows is an essential (matter) for performing (a perfect and correct) prayer. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.