JDBC Error

Dear friend,

I want to create a conection to postgreSQL database with "forte for java 4" and this returns an error message:

************************************************************
Driver cargado
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getConnection(DriverManager.java:532)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at Prueba.main(Prueba.java:26)

**************************************************************

this is the code:

*************************************************************************************
import java.sql.*;

public class Prueba
{
public static void main(String ar[])
{
try
{
String driver="org.postgresql.Driver";
Class.forName(driver);
System.out.println("Driver cargado");

String url="jdbc:tbase://192.168.0.20:5432";

Connection conn=DriverManager.getConnection(url,"postgres","internal");
System.out.println("conectado");

//Class.forName("org.postgresql.Driver");

}catch(Exception e)
{
e.printStackTrace();
}
}

}

please help me,

thank