Q: when the Imam climbs the stairs of the Minbar, can i still pray the two rak'at of tahiyyat Al-masjid (greeting of the masjid)?
A: Yes, brother. U must. If a person comes late to the Friday Prayer while the Imam is delivering the khutbah, should he pray the two rak`ahs of tahiyyat al-Masjid (prayer of greeting the mosque) and the sit or should he simply skip them? The strongest opinion is to perform the tahiyyat al-Masjid based on the Hadith of the Prophet (sallallahu `alaihi wa sallam): "If one of you comes to the Masjid, he should pray two rak`ahs before he sits" [Al-Bukhari and Muslim]. This requirement is limited only to prayers offered in a Masjid. I don't remember where I read this hadith, but the it goes like this: A man once went to the mosque while Muhammad (P.B.U.H) was delivering the Juma'a khutbah. He sat down to listen to the khutbah. Muhammad (P.B.U.H), during His khutbah, stopped, and addressed him, saying "Stand first, and pray Tahiyyat ul Masjid". Allah knows best.