private void handleAction() {
		if (actionButton.getText().equals("Find IP")) {
			Integer ip = dnsDB.findIP(nameText.getText());
			if (ip == null) {
				JOptionPane.showMessageDialog(GUI.this,
						"Could not find an IP address with host name: "
								+ nameText.getText());
			} else {
				ipText.setText(DNSDB.IPToString(ip));
			}
		} else if (actionButton.getText().equals("Find Host Name")) {
			Integer ip = DNSDB.stringToIP(ipText.getText());
			if (ip == null) {
				JOptionPane.showMessageDialog(GUI.this, "'" + ipText.getText()
						+ "' is not a valid IP address.");
			} else {
				String name = dnsDB.findHostName(ip);
				if (name == null) {
					JOptionPane.showMessageDialog(GUI.this,
							"Could not find a host name with IP address: "
									+ ipText.getText());
				} else {
					nameText.setText(name);
				}
			}
		} else if (actionButton.getText().equals("Test Name-IP Pair")) {
			Integer ip = DNSDB.stringToIP(ipText.getText());
			if (ip == null) {
				JOptionPane.showMessageDialog(GUI.this, "'" + ipText.getText()
						+ "' is not a valid IP address.");
			} else {
				boolean valid = dnsDB.testPair(ip, nameText.getText());
				if (valid) {
					JOptionPane.showMessageDialog(
							GUI.this,
							"'" + ipText.getText()
									+ "' is correctly mapped to '"
									+ nameText.getText() + "'.");
				} else {
					JOptionPane.showMessageDialog(GUI.this,
							"'" + ipText.getText()
									+ "' is not the IP address for '"
									+ nameText.getText() + "'.");
				}
			}
		}
	}