The T-V comedy “Friends” is fictional, but Iowans who play the Powerball lottery game can learn a valuable lesson from tonight’s episode. The Iowa-based Powerball is the focus of the show as Phoebe, Joey, Monica and the rest of the cast go bananas over a big jackpot. The Iowa Lottery’s Mary Neubauer says trouble quickly develops as the friends get in a “dust-up” over how to divide the winnings, even though none of them have won anything yet. Neubauer says Powerball players in the real world can avoid such conflicts.Players who are buying tickets for friends or co-workers should keep careful track of who pays and how much. She suggests making copies of all tickets along with the names of everyone who contributes. Neubauer says the game itself may be a big winner with tonight’s episode — in publicity. Neubauer says the show may spur ticket sales in Iowa and the 22 other states where Powerball is played, along with the District of Columbia and the U-S Virgin Islands. The show airs on N-B-C at 7 P-M.