Hi, Sorry, posted the previous one by error, this is what's missing in the code:
class APanel extends Panel(){ private List<B> selectedBs; public APanel(){ A a = getA(); List<B> choices = getBChoices(); cbmc = new CheckBoxMultipleChoice("id", choices); cbmc.setModel(new PropertyModel(this, selectedBs)); Form f = new Form("form"){ onSubmit(){ List<AB> abs = a.getAB(); abs.removeAll(); for (B b : selectedBs){ AB ab = new AB(a, b); abs.add(ab); } // a contains properly initialized ab elements } } f.add(cbmc); } Question is, does 'selectedBs' get serialized in pageMaps ? If so, I suppose it would be better to store only selectedB's id's... Thanks, and sorry again for the double-posting inconvenience ! Xavier