Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.

 

The Prophet (peace be upon him) said, “No man should stay with a lady in seclusion except in the presence of  a mahram (a relative who is permanently prohibited to get married with). A man stood up and said, “O Allah’s Messenger (peace be upon him)! My wife has gone out intending to perform the Hajj and I have been enrolled (in the army) for such-and-such campaign.” The Prophet (peace be upon him) said, “Return and perform the Hajj with your wife.”

 

Getting alone with a strange woman or man alone at the elevator is, thus, prohibited.

 

Allah Almighty knows best.