if (wpParent instanceof Project) {
Project project = (Project) wpParent;
dateBox.setSelectableDateRange(project.getStart(), project.getEnd());
} else if (wpParent instanceof WorkPackage) {
WorkPackage wp = (WorkPackage) wpParent;
dateBox.setSelectableDateRange(wp.getStart(), wp.getEnd());
}
for (WorkPackage child : workPackage.getSubWorkPackagesRec()) {
if (child == workPackage) {
continue;