public static AppServer getInstance(String strTypeConn) throws Exception
	{
		if (strTypeConn == null || strTypeConn.equals("Oracle"))
		{
			if (instanceOracle == null)
			{
				instanceOracle = new AppServer("Oracle");
			}
			return instanceOracle;

		}
		else if (strTypeConn == null || strTypeConn.equals("MySQL"))
		{
			if (instanceMySQL == null)
			{
				instanceMySQL = new AppServer("MySQL");
			}
			return instanceMySQL;

		}
		else if (strTypeConn == null || strTypeConn.equals("SQLServer"))
		{
			if (instanceSQLServer == null)
			{
				instanceSQLServer = new AppServer("SQLServer");
			}
			return instanceSQLServer;

		}
		throw new Exception("Unkown Instance");
	}