title: Detecting mouse clicks on a gameobject
body: <p>Here is my code that attached with the game object that I want to click </p>
  
  <pre><code>void Update () {
  
      if (Input.GetMouseButtonDown (0)) 
      {                    
              Application.LoadLevel("option");
  
  }
  </code></pre>
  
  <p>And it seems like I can click anywhere on screen for make "Application.LoadLevel("option");" run.</p>
  
  <p>How can I solve this problem?</p>