Problems with a shooting script

Questions & Answers
1

I’m having a problem with a shooting script that I got off of the Unity wiki.

“Weapon Script”

public class weaponScript : MonoBehaviour
{
// public
public float projMuzzleVelocity; // in metres per second
public GameObject projPrefab;
public float RateOfFire;
public float Inaccuracy;

// private
private float fireTimer;

// Use this for initialization
void Start () 
{
    fireTimer = Time.time + RateOfFire;
}

// Update is called once per frame
void Update () 
{
    Debug.DrawLine(transform.position, transform.position + transform.forward, Color.red);
    if (Time.time > fireTimer)
    {
        GameObject projectile;
        Vector3 muzzlevelocity = transform.forward;

        if (Inaccuracy != 0)
        {
            Vector2 rand = Random.insideUnitCircle;
            muzzlevelocity += new Vector3(rand.x, rand.y, 0) * Inaccuracy;
        }

        muzzlevelocity = muzzlevelocity.normalized * projMuzzleVelocity;

        projectile = Instantiate(projPrefab, transform.position, transform.rotation) as GameObject;
        projectile.GetComponent<projectileScript>().muzzleVelocity = muzzlevelocity;
        fireTimer = Time.time + RateOfFire;
    }
    else
        return;
}

}

“Projectile Script”

public class projectileScript : MonoBehaviour
{
public Vector3 muzzleVelocity;

public float TTL;

public bool isBallistic;
public float Drag; // in metres/s lost per second.

// Use this for initialization
void Start () 
{
    if (TTL == 0)
        TTL = 5;
    print(TTL);
    Invoke("projectileTimeout", TTL);
}

// Update is called once per frame
void Update () 
{
    if (Drag != 0)
        muzzleVelocity += muzzleVelocity * (-Drag * Time.deltaTime);

    if (isBallistic)
        muzzleVelocity += Physics.gravity * Time.deltaTime;

    if (muzzleVelocity == Vector3.zero)
        return;
    else
        transform.position += muzzleVelocity * Time.deltaTime;
    transform.LookAt(transform.position + muzzleVelocity.normalized);
    Debug.DrawLine(transform.position, transform.position + muzzleVelocity.normalized, Color.red);
}

void projectileTimeout()
{
    DestroyObject(gameObject);
}

}

I’m relatively new to Unity, and I have minimal experience with C sharp. To my knowledge, this script was made for Unity 3 however I think it should work in Unity 4. I keep on getting an error message that says “projPrefab is not defined”. How can I fix this problem? Should I find another script? How do I define “projPrefab”? The link to the page where I got this script is:

http://wiki.unity3d.com/index.php/ShootingWeaponScript

2 
public GameObject projPrefab;

You need to drag your projectile prefab (if u have made one) to that in the inspector window. At the moment it doesn’t know what it should instantiate. So for example, make a new cube, make a prefab of it, drag that prefab to the projPrefab in the inspector window. Then it will shoot cubes.