[Unity2D] Controlling HingeJoint2D motor

[Niikhawod]

Hi,

i’m new to Unity, i want to make a simple 2d vehicle game but i can’t figure out how i can controll the hingejoint motor with the keyboard.i have looked at the scripting reference but that explain anything i need to know.
i am using unity 4.3.3, and unityscript.

could some give me a small example of how i can control the hingejoint motor speed and torque ?

[Niikhawod]

i have found some code that i understand and that i got to work, but now there is another problem.
the motor is alway set back to zero even when i am holding down a key.

using System.Collections;

public class player : MonoBehaviour {

private HingeJoint2D hingeJoint2D;

private JointMotor2D jointMotor2D;
public KeyCode moveRight;
public KeyCode moveLeft;
public int MotorSpeed = 0;
// Use this for initialization

void Start () {

hingeJoint2D = GetComponent();

JointMotor2D motor = hingeJoint2D.motor;

motor.motorSpeed = 0;

hingeJoint2D.motor = motor;

Debug.Log("joint motor = " + jointMotor2D);

}

// Update is called once per frame

void Update () {

JointMotor2D motor = hingeJoint2D.motor;

if (Input.GetKey (moveRight)) {

motor.motorSpeed = (MotorSpeed + MotorSpeed + 100);

} else if (Input.GetKey (moveLeft)) {
motor.motorSpeed = (MotorSpeed + MotorSpeed + 100) * -1;

} else {
//if no key is pressed, stop the motor.
MotorSpeed = 0;
motor.motorSpeed = MotorSpeed;

}
Debug.Log (MotorSpeed);
hingeJoint2D.motor = motor;

}

}