Melvin Frank Bosetti of 907 Brown St.;Belle Vernon;died suddenly Wednesday;March 28;1984;at 12:30 p.m.in the Mon Valley Hospital.  He was 61.  Mr.Bosetti was born July 18;1922;in Smithton;a son of Mary Litterini Bosetti of Smithton and the late Frank Bosetti.  A resident of the Belle Vernon area for the past 29 years;he was a member of St.Sebatian Roman Catholic Church.  Mr.Bosetti;a U.S.Army veteran of World War II;was a member of Belle Vernon American Legion Post 659.  At the time of his death  he was employed as a millworker at the Monessen Plant of the Wheeling-Pittsburgh Steel Corp. In addition to his mother;survivors include his wife;Ann Praskavich Bosetti;two sons;Dennis A.and David C.Bosetti;both at home;one brother;Ralph Bosetti of Weirton;W.Va.;and one sister;Margaret Bosetti of Smithton.  Friends will be received Thursday from 7 to 9 p.m.and Friday from 2 to 4 and 7 to 9 p.m.in the Leonard J.Parzynski Funeral Home;626 Broad Ave.;Belle Vernon;where a Prayer service will be held Saturday;March 31;at 9:30 a.m;followed by a Mass of Christian Burial at 10 a.m.in St.Sebastian Roman Catholic Church;Belle Vernon.  Burial will be Belle Vernon Cemetery.  The Belle Vernon American Legion Post 659 will hold services on Friday at 7:15 p.m.in the funeral home.  The Leonard J.Parzynski Funeral Home is in charge of arrangements.