String[] siteSelectStrings = {"Site", "London", "Long Island"};
    JComboBox regSiteSelectBox = new JComboBox(siteSelectStrings);
    regSiteSelectBox.addItemListener(new ItemListener() {
        public void itemStateChanged(ItemEvent arg0) {
            getBuildingList gbl = new getBuildingList();
            regBuildingSelectBox.addItem(gbl.buildingSelectList((String)(regSiteSelectBox.getSelectedItem())));
            }
        });
    regSiteSelectBox.setBounds(24, 336, 282, 20);
    contentPane.add(regSiteSelectBox);


    regBuildingSelectBox = new JComboBox();
    regBuildingSelectBox.setBounds(24, 367, 282, 20);
    contentPane.add(regBuildingSelectBox);