Here you can find the source of warning(String msg)
public static void warning(String msg)
//package com.java2s; /* Copyright (C) 2001-2002 Taylor Gautier * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version.//from w w w. j a va 2s.c om * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * $Id: GUIUtilities.java,v 1.1 2002/08/05 00:06:41 tgautier Exp $ */ import javax.swing.*; public class Main { public static void warning(String msg) { Object[] options = { "Ok" }; JOptionPane.showOptionDialog(null, msg, "Warning", JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE, null, options, options[0]); } }