Hi Mirko,
to access the value of a radio button set, you use the value function. It is of no importance, upon which button widget you call it as long as it is in the same set (means: those radio buttons which share the same variable). To illustrate I rewrote your example code:
(defun radio-button-minimalist () (with-ltk() (let* ((gender-frame (make-instance 'frame :master nil)) (lbl_gender (make-instance 'label :master gender-frame :text "Sex ")) (rdb_m (make-instance 'radio-button :master gender-frame :text "Male" :variable "gender" :value "Male")) (rdb_f (make-instance 'radio-button :master gender-frame :text "Female" :variable "gender" :value "Female")) (text (make-instance 'text :master nil :width 20 :height 10)) (but (make-instance 'button :master nil :text "Push me" :command (lambda () (setf (text text) (format nil "The value of radio-button is: ~a" (value rdb_m)))) )) ) (setf *radio-button-minimalist* `(:text ,text)) (grid gender-frame 1 1) (grid lbl_gender 1 1) (grid rdb_m 1 2) (grid rdb_f 1 3) (grid but 2 1 :columnspan 2) (grid text 3 1 :columnspan 2))))
Peter