SpringJoint Unity Code

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SpringCompress : MonoBehaviour
{
    public Transform otherEnd; // The Other end of the spring that this object should try stay a set distance from
    public float targetDistance; // The distance this object should try keep from otherEnd
    public float springForce;
    private Rigidbody rigid;
    // Start is called before the first frame update
    void Start()
    {
        rigid = GetComponent<Rigidbody>();
    }

    // Update is called once per frame
    void FixedUpdate()
    {
        private float current = Vector3.Distance(transform.position, otherEnd.position);
        if(current > targetDistance) // Spring is extended
        {
            //Pull in spring
             transform.LookAt(otherEnd);
             rigid.AddRelativeForce(Vector3.forward * springForce);

        }
        else // spring is compressed
        {
            //extend Spring
            transform.LookAt(otherEnd);
            rigid.AddRelativeForce(Vector3.forward * -springForce);
        }
    }
}