Lisp plot withoyut pick by windowns (2 point on xref)

Hello everone. I want plot a drawing by select frame xref (adlayout before) instead of pick 2 point ( by windowns). I try write but failed, i hope everbody help me. Thank you very much!!. Have a good day

;CONG TY CP TU VAN XAY DUNG CONG TRINH 625

;P.TKCD - CIENCO625

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(prompt"\n[cmd : IN] - TDK - P.TKCD - CIENCO625")

;LIPS IN HANG LOAT - (31/12/2016)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun c:IN()

(prompt"\n[cmd : IN] - APPLY TO LAYOUT BEFORE")

(setq tl (getreal "\nNhap ty le in ban ve 1/ :"))

;quet chon cac xref

(princ "\nQuet chon xref:")

(setq sset (ssget (list '(0 . "INSERT") )))

(setq i 0)

(setq lmt (sslength sset))

(while (

(setq doituong (ssname sset i))

(setq laynd (entget doituong))

(setq p1 (cdr (assoc 10 laynd)))

(setq p2 (list (+ (car p1) 420) (+ (cadr p1) 297)))

(command "_plot" "y" "" "" "" "m" "" "" "w" p1 p2 tl "c" "y" "" "y" "" "n" "n" "n" "n" "y")

(setq i (+ i 1))

)

(princ))

E còn quá ít kiến thức để làm việc này