vdata_id	IN:	Vdata identifier returned by VSattach
	field_name_list	IN:	Name(s) of the fields to check

	Purpose	Computes the size, in bytes, of the given field(s) for the local machine.
	Return value	Returns the fields size if successful and FAIL (or -1) otherwise.
	Description	VSsizeof computes the size, in bytes, of the fields specified in the parameter field_name_list in the vdata identified by the parameter vdata_id.
		The parameter field_name_list specifies a single field or several comma-separated fields. The field or fields should already exist in the vdata. If more than one field is specified, VSsizeof will return the total sizes of all of the fields.

	FORTRAN	integer function vsfsiz(vdata_id, field_name_list)
		integer vdata_id
		character*(*) field_name_list