AutoLISP Help

I want to write a simple AutoLISP routine that will list the slope
between two entities be they points, nodes, polylines, 3dpolylines,
etc. I have the basic mathematics down, but I am having problems with
the remainder. Currently the program loads, but gets stuck in
initializing. I know I need to get the two points, but do not know
how to do this. Here is the program, can anyone help me finish it?

(defun ges( pt1 pt2 / dZ d Slope)
(setq
dZ (- (caddr pt2) (caddr pt1))
d (distance (list (car pt1) (cadr pt1) 0.0) (list (car pt2) (cadr
pt2) 0.0))
Slope (* 100.0 (/ dZ d))
)
)

 

Try this:

(defun c:ges( / dZ d Slope)
(setq Pt1 (getpoint "\nFirst point: "))
(setq Pt2 (getpoint Pt1 "\nSecond point: "))
(setq
dZ (- (caddr pt2) (caddr pt1))
d (distance (list (car pt1) (cadr pt1) 0.0) (list (car pt2)
(cadr
pt2) 0.0))
Slope (* 100.0 (/ dZ d))
)
(princ (strcat "Slope= " (rtos Slope 2 2) "%"))
(princ)
)

 

Hi,
please me a little sketch of the line, then I can help you

Arnold