title: JS, How to let a page only be loaded in another page as an iframe?
body: <p>I have two pages, one is <code>index.html</code> another is <code>iframe.html</code></p>
  
  <p>How to let the <code>iframe.html</code> only be loaded in <code>index.html</code>?</p>
  
  <p>If iframe in <code>other pages</code> or directly type <code>http://www.site.com/iframe.html</code> in browser, the page only show some words like <code>opps~~something is wrong.</code></p>
  
  <p>something like <code>bing shopping</code>.</p>
  
  <p>Thanks.</p>