[ltk-user] How to configure widgets?

[harven at free.fr]

> I am trying to make my first steps with ltk, and I have problems to
> reconfigure existing widgets. Here is an example where I try to reconfigure
> the :TEXT attribute of the LABEL-WIDGET widget whenever the checkbox of the
> CHECK-BUTTON-WIDGET widget is clicked.

Try with setf instead of configure, i.e.
(setf (text label-widget) val)
instead of 
(configure label-widget :text val)

Sincerely,
Harven