Selectmen have rescheduled the town election to coincide with the special US Senate primary elections on April 30, when voters statewide will head to the polls to choose the Democratic and Republican candidates who will vie to replace John Kerry. Selectmen had previously voted to hold the town election in early May . Town Clerk Patrick Ward said combining the elections could save the town about $45,000. Two candidates, Anthony Ishak, of Freeman Street, and Advisory Committee member Neil Wishinsky, have pulled nomination papers for a seat on the Board of Selectmen; there will not be an incumbent in the race, with Jesse Mermell stepping down last month after taking a job in the Patrick administration. The School Committee seats held by Helen Charlupski, Susan Wolf Ditkoff and Henry Warren will also be on the ballot this spring. The deadline for candidates to file nomination papers with the town clerk is March 12.