If a person comes a bit late to Minchah, and the tzibbur is about to begin shemoneh esrei, he should join them immediately in saying “shemoneh esrei.” After Minchah, he should say “ashrei,” but only as reciting pesukim, not as “the obligatory” ashrei.
The dvar Halacha for this week is that ohsek b’mitzvah parttur min hamitzvah, and seudas Purim with its accompanying festivities are eee efshar la’asohs ahl yedei acheirim!!
The prevalent custom is for the tzibbur to say the paragraph “Magen avos….” on Leil Shabbos when the chazzan says the berachah may’ayn sheva. When they are doing so, the chazzan should remain silent, and begin the paragraph only after the tzibbur has finished saying it.