private Statement cnx()
	{
		Statement st = null;
		try 
		{		
			if(usr != null && pwd != null && url != null)
			{
				Connection cnx = (Connection) DriverManager.getConnection(url, usr, pwd);
				st = (Statement) cnx.createStatement();	
			}	
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return st;
	}