* 抽出期間を変更し再検索する。
*/
public void periodChanged(int state) {
if (state == ItemEvent.SELECTED) {
int index = extractionCombo.getSelectedIndex();
NameValuePair pair = extractionObjects[index];
String value = pair.getValue();
int addValue = Integer.parseInt(value);
GregorianCalendar today = new GregorianCalendar();
today.add(GregorianCalendar.MONTH, addValue);
today.clear(Calendar.HOUR_OF_DAY);
today.clear(Calendar.MINUTE);