BILLERICA -- James P. Horan of Billerica died Thursday, Oct. 12, at the Jackson Memorial Hospital in Miami after a courageous battle with cystic fibrosis. He was 24.He was born in Lowell, April 30, 1982, son of James M. Horan of Billerica and Kathleen P. Randall of Chelmsford.He attended Billerica schools and continued his education at Clark University. He enjoyed martial arts, playing Texas Holdem poker, working on his computer, and spending time with his family. His family also said that Mr. Horan wanted to express special thanks to Shirley Guthrie and Josh Gulinello, for being lung-transplant donors.Besides his parents, he is survived by a sister, Noelle Horan of Chelmsford; his maternal grandmother, Nancy Lind of Billerica; his paternal grandparents, Jack and Susan Horan of Newfield, N.H.; his aunts and uncles, John Horan Jr. and Debbie Horan of Billerica, Donna Menegus of Falmouth, Patricia and David Keefe of Medford, Paula McMahan of Swansea, N.H., Joseph and Michelle Horan of Billerica and Shirley and Charlie Guthrie of Billerica. Mr. Horan also leaves many cousins and was the proud godfather of Chloe and Jason Horan.He was also the grandson of the late Geraldine Horan.