GameCamera.cs

using UnityEngine;
using System.Collections;

public class GameCamera : MonoBehaviour {
	
	private Transform target;
	private float maxX = 0f;
	private int buttonWidth = 400;
	private int buttonHeight = 100;
	private bool buttonShown=false;
	public int currentLevel = 0;
	public int nextLevel = 0;
	public OutPortal exit;
	public GUIStyle gStyle;
	
	
	public void setTarget(Transform t) {
		target = t;
	}
	
	void OnGUI() {
		if (!exit.hitP){
			if(!target){
				Invoke ("showButton", 1.55f);		
			}
			if (buttonShown && !target){
				if (GUI.Button (new Rect(Screen.width /2 - buttonWidth/2, Screen.height /2 - buttonHeight/2, buttonWidth, buttonHeight), "YOU HAVE DIED", gStyle)) {
					Application.LoadLevel (currentLevel);
				}
			}
			else{
				buttonShown=false;
			}
		}
		else{
			if (GUI.Button (new Rect(Screen.width /2 - buttonWidth/2, Screen.height /2 - buttonHeight/2, buttonWidth, buttonHeight), "LEVEL COMPLETE", gStyle)) {
				Application.LoadLevel (nextLevel);
			}
	
		}
	}
	
	void showButton(){
		buttonShown=true;
	}
	
	void LateUpdate() {
		if (target) {
			float x = target.position.x;
			if (x > maxX) {
				transform.position = new Vector3(x,transform.position.y,transform.position.z);
				maxX = x;
			}
		}
	}
}