A 26-million dollar addition at Prairie Meadows Race Track and Casino is finished and operators hope it will boost lagging attendance. Attendance at the Altoona facility dropped in 2000, especially during November and December. Prairie Meadows spokeswoman Daryl Lewis believes construction work at the casino kept some would-be patrons away.Lewis says cold weather and the opening of the Lakeside Casino in Osceola hurt attendance, too. The 50-thousand square foot addition more than doubles the size of the facility.Lewis hopes the extra space will alleviate the cramped spacing as the added space gives them more room for slot machines and a new air-handling system helps clear smoke from the casino. Other additions include a new grand entrance, gift shop, and coat check.