attributeValues.setMaximumSize(comboBoxMaximumSize);
attributeValues.setPreferredSize(comboBoxMaximumSize);
gridBagConstraints.gridx++;
panel.add(attributeValues, gridBagConstraints);
//set focus to attributeNames
panel.addHierarchyListener(new HierarchyListener() {
public void hierarchyChanged(HierarchyEvent e) {
final Component component = e.getComponent();
if(component.isShowing()){
attributeNames.requestFocus();
component.removeHierarchyListener(this);