mainPanel.add(new JLabel(msg), BorderLayout.NORTH);
JPanel p = new JPanel(new GridBagLayout());
mainPanel.add(p, BorderLayout.CENTER);
AutoCompletionManager autocomplete = Main.main.getEditLayer().data.getAutoCompletionManager();
List<AutoCompletionListItem> keyList = autocomplete.getKeys();
Collections.sort(keyList, defaultACItemComparator);
keys = new AutoCompletingComboBox(key);
keys.setPossibleACItems(keyList);
keys.setEditable(true);
keys.setSelectedItem(key);
p.add(Box.createVerticalStrut(5),GBC.eol());
p.add(new JLabel(tr("Key")), GBC.std());
p.add(Box.createHorizontalStrut(10), GBC.std());
p.add(keys, GBC.eol().fill(GBC.HORIZONTAL));
List<AutoCompletionListItem> valueList = autocomplete.getValues(getAutocompletionKeys(key));
Collections.sort(valueList, usedValuesAwareComparator);
final String selection= m.size()!=1?tr("<different>"):m.entrySet().iterator().next().getKey();
values = new AutoCompletingComboBox(selection);