java.sql.SQLException: No suitable driver

HI:
I'M TRYING TO CONNECT AN ECLIPSE 3.01 IDE RUNNING ON WINDOWS XP WITH A DB
POSTGRESQL VERSION 7.4.7. I USED THE FOLLOWINGS DRIVERS: PG.74.213/4/5/6.JDBC3.JAR
AND NO ONE WORKS.

THE MESSAGE WAS THE FOLLOWING:
Cargando clase
IWAV0055I Java Bean frenchconn.connpost started with the main method
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at frenchconn.connpost.agregarCliente(connpost.java:33)
at frenchconn.connpost.main(connpost.java:69)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.ve.internal.java.vce.launcher.remotevm.JavaBeansLauncher.main(JavaBeansLauncher.java:86)

AND THE CODE (MY CODE):

import java.sql.*;
import java.sql.DriverManager;
import java.sql.PreparedStatement;

//import samples.jdbc.JDBCTest;

/**
* @author Benjamin
*
* TODO To change the template for this generated type comment go to
* Window - Preferences - Java - Code Style - Code Templates
*/
public class connpost {

static {
System.out.println("Cargando clase");
}

public void agregarCliente(long idCliente,
String nombre) {
try {
String url = "jdbc:postgres://172.16.100.110:5432/benjamin";
Connection conn = null;
conn = DriverManager.getConnection(url,"benjamin", "benja1");
DriverManager.getDriver("org.postgresql.Driver");

String sql =
"INSERT INTO Cliente " +
"(IdCliente, Nombre) " +
"VALUES (?,?)";

PreparedStatement ps =
conn.prepareStatement(sql);

ps.setLong(1, idCliente);
ps.setString(2, nombre);

ps.executeUpdate();

ps.close();

conn.close();

System.out.println("Cliente insertado OK");
}
catch (Exception ex) {
ex.printStackTrace();
}
}

public static void main(String[] args) {

try {
// Cargo el driver JDBC de postgres
Class.forName("org.postgresql.Driver");

connpost conn = new connpost();
//jdbcTest.agregarCliente(1, "Pepe");
//jdbcTest.agregarCliente(2, "Juan");
conn.agregarCliente(123,"pepe");

// jdbcTest.transaccion();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
}

THANKS FOR EVERYTHING TO ANYONE

BENJAMIN