West Palm Beach, Florida-The parents of a five-year-old girl from West Palm Beach have sued McDonald's Corporation claiming its french fries contained a wheat protein that caused their daughter to become seriously ill.Mark and Theresa Chimiak of Jupiter say in the lawsuit filed on Saturday in Palm Beach Circuit Court that their daughter Annalise had an intolerance to gluten.The Chimiaks say they filed the lawsuit after McDonald's acknowledged earlier in the week that wheat and dairy ingredients were used in cooking oil for french fries.The family's attorney, Brian W. Smith, says the family had checked with McDonald's before she ate the fries and were assured the product was gluten-free.Jack Daly, senior vice president of McDonald's, said in an e-mail to The Palm Beach Post that the company is conducting research to determine if the fries have no gluten.