LONDON – David Haye and Dereck Chisora promised that the knockout loser of their non-world title fight on Saturday will donate $31,000 to charity.At a joint news conference on Wednesday, where the bitter British rivals were separated by a metal fence, one of the only two things they agreed on was helping out charities if one or the other is knocked out at Upton Park.Chisora (15-3) picked a children’s hospital, and Haye (25-2) chose a bone marrow charity for minorities.They also agreed to blood testing for doping, if asked. Otherwise, the banter flowed freely between the boxers, who have attracted an impressive 29,000 spectators so far to their grudge match.‘’I can’t think of such a fast-selling fight involving so much publicity since we bought Mike Tyson back, over 10 years ago,’’ said Frank Warren, Chisora’s manager.Haye and Chisora came to blows in an infamous press conference confrontation in Munich after Chisora’s defeat on points to Vitali Klitschko in February.The brawl tarnished the reputation of both men, leading to the Luxembourg Boxing Federation sanctioning their fight, and not the British Boxing Board of Control. Neither boxer was apologetic for the ugly scenes that were broadcast globally from Munich.‘’I regret saying I would shoot David,’’ Chisora said. ‘’But do I regret getting hit on the sucker punch? No.’’Haye said: ‘’I don’t regret anything. I was defending myself like anyone else would.’’