whats wrong with this update

[jannoy]

update history2_detail set duration='$val_dur',up='1',resp_time=(resp_time + $resptime),ave_resp_time=(ave_resp_time + $ave_last),cum_up=(cum_up + $cum_up),compare_ratio='$comparenow',banner_result='$tmp_result' where id='$id' AND datenow=$datenow";

it seems it doesnt update the history2_details

the ave_resp_time is the same as previous

[sid]

print out the assembled query and see if all variables actually have the value you expect.