Fw:gdb

[hz50241027]

Dear gdb group:
    I am a new user of gdb. I have a stupid problems. When I set breakpoint in my program, it seems that I can only set at the function. When I set in a line of my code, it won't stop.For example, I can set the break point at MatGetOwnershipRange(by break MatGetOwnershipRange ), but if I want to stop at  do 10, II=Istart+1,Iend by (break do 10, II=Istart+1,Iend), it won't stop there.
       i1 = 1
       m       = NN
       n       = NN
       five    = 27
       call PetscOptionsGetInt(PETSC_NULL_CHARACTER,'-m',m,flg,ierr)
       call PetscOptionsGetInt(PETSC_NULL_CHARACTER,'-n',n,flg,ierr)
       call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr)



       call MatCreate(PETSC_COMM_WORLD,A,ierr)
       call MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n,ierr)
       call MatSetType(A, MATAIJ,ierr)
       call MatSetFromOptions(A,ierr)
      call MatMPIAIJSetPreallocation(A,five,PETSC_NULL_INTEGER,five,            &
     &                     PETSC_NULL_INTEGER,ierr)
       call MatSeqAIJSetPreallocation(A,five,PETSC_NULL_INTEGER,ierr)


       call MatGetOwnershipRange(A,Istart,Iend,ierr)


       do 10, II=Istart+1,Iend
         ROW_NUM=SPAI(II+1)-SPAI(II)
             ALLOCATE(NCOL_PERROW(ROW_NUM),VALUE_PERROW(ROW_NUM))
             KVAL_START=SPAI(II)
             KVAL_END=SPAI(II+1)-1
             NCOL_PERROW=SPAJ(KVAL_START:KVAL_END)
             VALUE_PERROW=SPAA(KVAL_START:KVAL_END)
        call  MatSetValues(A,i1,II-1,ROW_NUM,NCOL_PERROW,VALUE_PERROW,INSERT_VALUES,ierr)
             DEALLOCATE(NCOL_PERROW,VALUE_PERROW)
  10   continue

Another problem is that when I stop at MatGetOwnershipRange, I want to see the value of i1 by print i1, it shows No symbol "i1" in current context.