lisp routine for

Hi can somebody tell me what's wrong with this program

it doesn't work

this is a routine to draw a connection piece of two round air ducts with different dimensions. For example to connect a duct with diameter 20 cm to a duct with diameter 40 cm.

The reduction must have a specific angle to prevent turbulent air flows (typical 15°) and has a collar of 5 cm on both ends to connect with te ducts.

(defun c:verloop (/ p1 p2 p3 p4 dia1 dia2 r1 r2 c1 c2 c3 c4 verschil rad15 tan15 dy l)
 
 (setq p1 (getpoint "\nStart point :  "))
 (setq dia1 (getdist "\n first diameter :  "))
 (setq r1 (/ dia1 2))
 (setq dia2 (getdist "\n second diameter :  " ))
 (setq r2 (/ dia2 2))
 (command "circle" p1 r1 )
 (setq c1 (entlast))
 
 (setq p2 (list (car p1) (cadr p1) (+ (caddr p1) 5)))
 (command "circle" p2 r1 )
 (setq c2 (entlast))
 
 (setq verschil (abs (- dia1 dia2)))            
 (setq rad15 (/ (* 15 pi) 180))                 
 (setq tan15 (/ (sin rad15) (cos rad15) ) )
 (setq dy(/ verschil 2))                        
 (setq l(/ dy tan15))   
                       
 (setq p3 (list (car p2) (cadr p2) (+ (caddr p2) l))) 
 (command "circle" p3 r2)
 (setq c3 (entlast))
 (setq p4 (list (car p3) (cadr p3) (+ (caddr p3) 5)))
 (command "circle" p4 r2)
 (setq c4 (entlast))
 (command "loft" c1 c2 c3 c4 "" "" r "")

)

This works good on my end

Just change the last line on this one:

(command "loft" c1 c2 c3 c4 "" "" r)

And also don't forget to set OSMODE to 0

before you will be draw something with command, then

restore it back

~'J'~