So far my script is below. I am attempting to create another Collider part to the script, I am attempting to make it so when you collide with Lava, which has a Tag named lava, the player will die. However, I can't get it to call for the die function and I also can't use OnTriggerEnter(collider,other) as it gives me an error.
using UnityEngine;
using System.Collections;
public class PlayerController : MonoBehaviour
// Player Movement Start
{
    public float speed;
    private Rigidbody rb;
    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }
    void FixedUpdate()
    {
        float moveHorizontal = Input.GetAxis("Horizontal");
        float moveVertical = Input.GetAxis("Vertical");
        Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);
        rb.AddForce(movement * speed);
    }
            //End of Player Movement Script
    //Pickups Script
    void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.CompareTag("Pick Up"))
        {
            other.gameObject.SetActive(false);
        }
    }
        //End of Pickups Script
    //Health and Death Script
    public float health;                
    public GameObject Ragdoll;             
    public void TakeDamage(float dmg){
        health -= dmg;
        if (health <= 0) {
            Die();
        }
    }
    public void Die() {
        Application.LoadLevel(Application.loadedLevel);
    }
 }
//End of Health and Death script
 
     
     
    