The state can only pay for an extra year of preschool for a quarter of the estimated 5,000 four-year-olds who will be affected next year when junior kindergarten is eliminated at public schools. The state Department of Human Services will ask lawmakers for an extra 2-and-a-half million dollars to  help needy families afford another year of preschool.The change comes as the state's higher age requirement for kindergarten takes effect.   Students will need to be five years old by July 31 to enroll in kindergarten for the 2014-15 school year.  The state plans to phase out junior kindergarten and introduce publicly funded universal preschool. Hawaii is one of 11 states without state-funded preschool.