Blue jeans, the uniform of young and old generations ,are losing their popularity.According to a study by Jeans Wear Communications,Jeans sales in the United States dropped from 502 million pairs ten years ago to 387 million pairs last year.Experts say that the decrease in sales will continue.Why is there the great decrease?Some fashion experts say it is because of the aging baby-boomer generation,They say that customers in their thirties and forties no longer have the body shape to wear the form-fitting trousers.Others say it is because there are few people in the 14 to 24-year-old population group. Also,boys used to buy a lot of jeans.Today they are choosing more stylish shorts,bicycle shorts,and cotton pants.Jeans manufacturers are trying to find ways to deal with the decrease in sales.Some are making pants for the aging generation-loose cotton trousers and a special design of their classic"503"jeans that have extra room in the seat.Other manufacturers are trying to increase their oversea sales.While jeans are less popular in the United States,they continue to be important fashion items in parts of Europe and Far East.