C+
C NAME:
C	write_read_bad_src.f
C PURPOSE:
C	To write and read a bad source from a file. Used to continue to eliminate bad sources from the tomography program
C CATEGORY:
C	write and read a file
C CALLING SEQUENCEi
C	call write_read_bad_src(iLU,cfile,isrcread,NBS,cSRC)
C INPUTS:
C	iLU		integer		logical unit opened or closed
C	cfile		character*10	file name bad_source
C	isrcread	integer		0  - don't write or read sources
C					1  - write out bad velocity sources
C					10 - read in bad velocity sources
C					2  - write out bad density sources
C					20 - read in bad density sources
C 	NBS		integer		number of the bad source
C	cSRC		character*115	Source description
C	input file
C
C OUTPUTS:
C	output file
C
C RESTRICTIONS:
C
C PROCEDURE:
C
C MODIFICATION HISTORY:
C	2018 MAY B.Jackson (UCSD)
C-
	subroutine write_read_bad_src(iLU,cfile,isrcread,NBS,cSRC)
C
	character	cfile*10
	character	cSRC*115


	close(13)

	open (13, file=cFile1,status='old',recl=1000,access='sequential',form='formatted',iostat=iReaddata)

	  if(isrcread.eq.0) then
	    print *, 'No sources read or written'
	    return
	  end if

	  if(isrcread.eq.1) then					! write out a velocity source number and description
	    write (ilu,'(I10,A)',iostat=iWriteV) NBS, cSRC
	    if(iWriteV.ne.0) return
	  end if

	  if(isrcread.eq.10) then					! read in a velocity source number
	    read (ilu,'(I10)',iostat=iReadV) NBS
	    if(iReadV.ne.0) return
	  end if

	  if(isrcread.eq.2) then					! write out a velocity source number and description
	    write (ilu,'(I10,A)',iostat=iWriteGN) NBS, cSRC
	    if(iWriteGN.ne.0) return
	  end if

	  if(isrcread.eq.20) then					! read in a velocity source number
	    read (ilu,'(I10)',iostat=iReadGN) NBS
	    if(iReadGN.ne.0) return
	  end if

	 return
	end