// Check if level at index 1 can be loaded.
// If it can be loaded then load it.
function Update() {
    if (Application.CanStreamedLevelBeLoaded(1)) {
          Application.LoadLevel(1);
    }
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Update() {
        if (Application.CanStreamedLevelBeLoaded(1))
            Application.LoadLevel(1);
        
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Update():
        if Application.CanStreamedLevelBeLoaded(1):
            Application.LoadLevel(1)

// Check if "Level1" can be loaded, if it can be loaded then load it.
function Update() {
    if (Application.CanStreamedLevelBeLoaded("Level1")) {
          Application.LoadLevel("Level1");
    }
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Update() {
        if (Application.CanStreamedLevelBeLoaded("Level1"))
            Application.LoadLevel("Level1");
        
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Update():
        if Application.CanStreamedLevelBeLoaded('Level1'):
            Application.LoadLevel('Level1')