Help with wall code

This code draws walls with central lines and assigns layers according to the thickness of the wall.

I am sure that some of the Gurus can help me improving it as follows:

· Get rid of the nasty “; error: bad argument type: 2D/3D point: nil” message when enter the last point

· Having the wall lines filleted when the end point of the last wall is the first point of the first wall (walls closing to form a room).

· Having the wall lines (not the center line) filleted when there are T or X intersections.

· Cleaning the code, to have a better solution.

Thanks in advance and my apologies for the poor way of writing codes.

*no code attached*

Dumb of me, here is the code:

(defun c:walls (/ f1 pnt4 f2 c d e pnt1 pnt3 pnt2 pnt5 pnt6 ang lac laca ee f11 f21)

(setvar "osmode" 0)

(command "fillet" "r" 0)

(setq f1 nil)

(setq pnt4 nil)

(setq f2 nil)

(setq c 0)

;;;;;-------------------------------------------------------

(if (not *WID) (setq *WID 0.15))

(princ "\nENTER WALLS WIDTH:

(PRINC *WID)

(SETQ WID (GETDIST ">: " ))

(IF (NOT WID) (SETQ WID *WID) (SETQ *WID WID))

(SETQ MWID ( / WID 2))

;;;;;;;----------------------------------------------------

(SETQ EE ( * WID 100))

(SETQ EE (RTOS EE 2 0))

(setq Lac (strcat "WALLS-BLINE-" EE))

;;;;;;-----------------------------------------------------

(setq e 3)

(setq pnt1 (getpoint "\nFIRST POINT OF WALL "))

(while e

(if (/= pnt3 nil) (setq f1 pnt3))

(if (> c 1) (setq f1 (polar pnt3 aNG mWID)))

(if (/= pnt3 nil) (setq f11 pnt5))

(if (> c 1) (setq f11 (polar pnt5 aNG mWID)))

(setq pnt2 (getpoint "\nNEXT POINT " pnt1))

(setq c (+ c 1))

(setq aNG (angle pnt1 pnt2))

(setq pnt3 (polar pnt1 (- aNG (dtr 90)) MWID))

(setq pnt4 (polar pnt2 (- aNG (dtr 90)) MWID))

(setq pnt5 (polar pnt1 (+ aNG (dtr 90)) MWID))

(setq pnt6 (polar pnt2 (+ aNG (dtr 90)) MWID))

(COMMAND "LAYER" "MAKE" LAC "COLOR" "6" "" "LTYPE" "CENTER" "" "")

(command "line" pnt1 pnt2 "")

(setq LacA (strcat "WALLS-" EE))

(IF (

(COMMAND "LAYER" "MAKE" Laca "COLOR" 2 "" "ltype" "continuous" "" "")

(COMMAND "LAYER" "MAKE" Laca "COLOR" 4 "" "ltype" "continuous" "" ""))

(command "line" pnt3 pnt4 "")

(command "line" pnt5 pnt6 "")

(setq f2 (polar pnt2 (- aNG (dtr 90)) mWID))

(setq f21 (polar pnt2 (+ aNG (dtr 90)) mWID))

(setq pnt1 pnt2)

(if (/= f1 nil) (command "fillet" f1 f2))

(if (/= f11 nil) (command "fillet" f11 f21))

(COMMAND "LAYER" "SET" "0" "")

)

(princ)

)