;; | -----------------------------------------------------------------------------
;; | SS_KeepTypes
;; | -----------------------------------------------------------------------------
;; | Function : Keeps only given object types in a selection set and returns them
;; | Arguments:
;; |            'ss'      - Seelction Set to process
;; |            'TypeLst' - ObjectType(s) to keep
;; | Returns  : The new selection set
;; | Updated  : July 31, 2002
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | -----------------------------------------------------------------------------


(defun SS_KeepTypes ( ss TypeLst / cnt ss1 ssl ename entl en )

(setq ss1 nil)
(if (and ss (> (setq ssl (sslength ss)) 0))
(progn
	(setq
		cnt 0
		ss1 (ssadd)
	)
	(repeat ssl
		(setq
			ename (ssname ss cnt)
			entl  (entget ename)
			en    (LI_item 0 entl)
			cnt   (1+ cnt)
		)
		(if (member en TypeLst)
			(ssadd ename ss1)
		)
	)
))

(if (and ss1 (> (sslength ss1) 0)) ss1 nil)
)