Whether the drive should attempt to reach position, velocity, both or nothing.

	// Create a JointDrive, configure it and assign the JointDrive to
	// the zDrive element of a configurable joint.
	
	function Start() {
		var joint : ConfigurableJoint = gameObject.AddComponent(ConfigurableJoint);
		joint.targetPosition = Vector3(0,0,-10);
		
		var drive : JointDrive = JointDrive();
		drive.positionSpring = 50;
		drive.mode = JointDriveMode.Position;
		
		joint.zDrive = drive;
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Start() {
        ConfigurableJoint joint = gameObject.AddComponent<ConfigurableJoint>();
        joint.targetPosition = new Vector3(0, 0, -10);
        JointDrive drive = new JointDrive();
        drive.positionSpring = 50;
        drive.mode = JointDriveMode.Position;
        joint.zDrive = drive;
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Start() as void:
		joint as ConfigurableJoint = gameObject.AddComponent[of ConfigurableJoint]()
		joint.targetPosition = Vector3(0, 0, -10)
		drive as JointDrive = JointDrive()
		drive.positionSpring = 50
		drive.mode = JointDriveMode.Position
		joint.zDrive = drive