VTM_INI_XML Function

  function VTM_INI_XML(filename) result(E_IO)
  !---------------------------------------------------------------------------------------------------------------------------------
  !!The VTK_VTM_XML function is used for initializing a VTM (VTK Multiblocks) XML file that is a wrapper to a set of VTK XML files.
  !---------------------------------------------------------------------------------------------------------------------------------

  !---------------------------------------------------------------------------------------------------------------------------------
  implicit none
  character(*), intent(IN):: filename ! file name
  integer(I4P)::             E_IO     ! Input/Output inquiring flag: $0$ if IO is done, $> 0$ if IO is not done
  !---------------------------------------------------------------------------------------------------------------------------------

  !---------------------------------------------------------------------------------------------------------------------------------
  Unit_VTM=GetUnit()
  open(unit   = Unit_VTM,       &
       file   = trim(filename), &
       form   = 'FORMATTED',    &
       access = 'SEQUENTIAL',   &
       action = 'WRITE',        &
       iostat = E_IO)

  write(unit=Unit_VTM,fmt='(A)',iostat=E_IO)'<?xml version="1.0"?>'
  write(unit=Unit_VTM,fmt='(A)',iostat=E_IO)'<VTKFile type="vtkMultiBlockDataSet" version="1.0"'// &
                                            ' byte_order="BigEndian" compressor="vtkZLibDataCompressor">'
  vtm_indent = 2
  write(unit=Unit_VTM,fmt='(A)',iostat=E_IO)repeat(' ',vtm_indent)//'<vtkMultiBlockDataSet>'
  vtm_indent = vtm_indent + 2
  blk = -1
  return
  !---------------------------------------------------------------------------------------------------------------------------------
  endfunction VTM_INI_XML