private void showLicense() {
// if (!(new File("license/AcceptedLicense")).exists()){
if (!(new File(Constant.getInstance().ACCEPTED_LICENSE)).exists()){
LicenseFrame license = new LicenseFrame();
license.setVisible(true);
while (!license.isAccepted()) {
try {
Thread.sleep(100);
} catch (InterruptedException e) {}
}
}