Java and SQL Server 2008 project using JDBC-ODBC Bridge

See more:

Java

SQL

I am working on my very first Java application that connects with MS SQL Server 2008, I have followed instructions on how to set classpaths( when using sqljdbc or jtds ), and how to configure JDBC-ODBC data sources either using the old SQL Server ODBC or SQL Server Native Client 10. then coded in java, when I try to establish a connection, I get the message like the one below

[Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

try
        {
            String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
            Class.forName( driver );

            String url = "jdbc:odbc:LoginTest";
            con = DriverManager.getConnection( url, "", "" );
            st = con.createStatement();
        }
        catch( Exception ex )
        {
            //JOptionPane.showMessageDialog( null, ex.getMessage() );
            System.err.println("SQL Exception : " + ex.getMessage() );
        }

Can someone please help me, I do not know what could be the problem because I have tried all the drivers but I still get the same message.
Thanx in advance!