a woman was robbed while she was on the way to visit her son at the douglass houses, at 140 w. 104th st. between columbus and amsterdam avenues. cops said that on dec. 31 at 6 p.m., two robbers followed her into the elevator. one thief put the 58-year-old mother in a chokehold while the other stole money from her pockets and took her purse. the thieves split, according to police, with one getting off on the 12th floor and the other on the 13th. the woman was taken to st. luke's hospital.