Access another script

Basically Im trying to access a function GetLives() in a script called obj. However Im having an error in my function update when I run the game.

using UnityEngine;
using System.Collections;

public class PickUpController : MonoBehaviour 
{
    public int objCount;
    public GameObject playerHandle;
    GUISkin gskin;

    void OnGUI() 
    {
        if(gskin)
        {
            GUI.skin = gskin;
        }

        string guistring = "Candy: " +objCount;
        guiText.text = guistring;
        GUI.Label (new Rect( 20, Screen.height-230, 150, 250), guistring);
    }

    void Update()
    {
        playerHandle = GameObject.Find("Player");//reference to the Player GameObject within the scene
        obj other;
        other = playerHandle.GetComponent("obj") as obj;
        objCount= other.GetLives();
    }
}

You need something like this:

...
playerHandle = GameObject.Find("Player");//reference to the Player GameObject within the scene
...

    playerHandle = GameObject.Find("Player");
    obj other;
    other = (other)playerHandle.GetComponent(typeof(obj));
    objCount= other.GetLives();