vdata_id	IN:	Vdata identifier returned by VSattach
	interlace_mode	IN:	Interlace mode of the data to be stored in the vdata

	Purpose	Sets the interlace mode of a vdata.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	VSsetinterlace sets the interlace mode of the vdata, vdata_id, to that specified by the parameter interlace_mode. This routine can only be used when creating new vdatas with write access.
		The value of interlace_mode may be either FULL_INTERLACE (or 0) or NO_INTERLACE (or 1). If this routine is not called, the default interlace mode of the vdata is FULL_INTERLACE. The FULL_INTERLACE option is more efficient than NO_INTERLACE although both require the same amount of disk space.
		Specifying FULL_INTERLACE accesses the vdata by record; in other words, all values of all fields in a record are accessed before moving to the next record. Specifying NO_INTERLACE accesses the vdata by field; in other words, all field values are accessed before moving to the next field. Thus, for writing data, all record data must be available before the write operation is invoked.
		Note that the interlace mode of the data to be written is specified by a parameter of the VSwrite routine.

	FORTRAN	integer function vsfsint(vdata_id, interlace_mode)
		integer vdata_id, interlace_mode