On Tue, Dec 08, 2020 at 08:38:36PM +0100, cage wrote: Hi! By the way does this code works as you wanted in you message? I am using nodgui because includes a modal inputbox but could be easily translated to LTK. ---8<-------8<-------8<--------- (in-package :nodgui) (defun ask-point (title message) (parse-integer (nodgui.mw:text-input-dialog *tk* title message))) (defun draw-line (canvas) (let ((x1 (ask-point "point?" "x1?")) (x2 (ask-point "point?" "x2?")) (y (/ (canvas-h canvas) 2))) (make-line canvas (list x1 y x2 y)))) (with-nodgui () (let ((canvas (make-canvas nil :width 300 :height 300))) (configure canvas :background "#FFFFFF") (pack canvas) (draw-line canvas))) ---8<-------8<-------8<--------- The code above is licensed FWIW with MIT license https://opensource.org/licenses/MIT bye! C.