I have top-down shooter (Something like dead frontier) and i want to make a flamethrower but i dont know how so please if you know how then please help me. I know i have to have a particle emitter but i dont know how to make the scripts. I have a basic gun that shoots and i used this script:

using UnityEngine;
using System.Collections;

public class BulletScript : MonoBehaviour {
    private float moveSpeed = 30f; 
    private float timeSpentAlive; 
    private GameObject objPlayer;
    private VariableScript ptrScriptVariable;

    // Use this for initialization
    void Start () {
        objPlayer = (GameObject) GameObject.FindWithTag ("Player");
        ptrScriptVariable = (VariableScript) objPlayer.GetComponent( typeof(VariableScript) );
    }

    // Update is called once per frame
    void Update () {
        timeSpentAlive += Time.deltaTime;
        if (timeSpentAlive > 1) 
        {
            removeMe();
        }
        // move the bullet
            transform.Translate(0, 0, moveSpeed * Time.deltaTime);
            transform.position = new Vector3(transform.position.x,0,transform.position.z); // because the bullet has a rigid body we don't want it moving off it's Y axis
    }
    void removeMe ()
    {
        Instantiate(ptrScriptVariable.parBulletHit, transform.position, Quaternion.identity );
        Destroy(gameObject);
    }
    void OnCollisionEnter(Collision Other)
    {
        if ( Other.gameObject.GetComponent( typeof(AIscript) ) != null && Other.gameObject != objPlayer ) // if we have hit a character and it is not the player
        {
            AIscript ptrScriptAI = (AIscript) Other.gameObject.GetComponent( typeof(AIscript) );
            ptrScriptAI.health -= 10;
            Instantiate(ptrScriptVariable.parAlienHit, transform.position, Quaternion.identity );
            removeMe();
        }
        removeMe(); // remove the bullet if it has hit something else apart from an enemy character
    }
}