;;;Elise Moss
;;;www.mossdesigns.com
;;;August 2005
;;;;;;this routine switches the start and endpoints of a line
;;;;;;

(defun c:swline ()
  ;;; get the line
 (setq ent (car (entsel "\nSelect a line to swap endpoints: ")))
 ;;get entity data
 (setq ent-data (entget ent))
 ;;verify a line was selected
 (setq ent-type (cdr (assoc 0 ent-data)))
 (while	(/= ent-type "LINE")
   (alert "A line was not selected - Try again.")
;;;get the line
   (setq ent (car (entsel "\nSelect a line to swap endpoints: ")))
   ;;get entity data
   (setq ent-data (entget ent))
   ;;verify a line was selected
   (setq ent-type (cdr (assoc 0 ent-data)))
 )					;end while
 ;;now a line has been selected and verified
  ;;;get the start point and end point
  (setq start-point (cdr (assoc 10 ent-data)))
  (setq end-point (cdr (assoc 11 ent-data)))
  ;;;swap the endpoints
  (setq ent-data (subst (cons 10 end-point) (assoc 10 ent-data) ent-data))
  (setq ent-data (subst (cons 11 start-point) (assoc 11 ent-data) ent-data))
  (entmod ent-data)
  (alert "Line endpoints have been swapped!")
  


)
	     ;;;end defun