title: how to put"like button" of facebook and twitter in my website?
body: <p>I want to put "like" button of facebook in my website, I use this </p>
  
  <pre><code>&lt;html&gt;
      &lt;head&gt;
        &lt;title&gt;My Great Web page&lt;/title&gt;
      &lt;/head&gt;
      &lt;body&gt;
         &lt;iframe src="http://www.facebook.com/plugins/like.php?href=https://www.google.com.sg/"
          scrolling="no" frameborder="0"
          style="border:none; width:450px; height:80px"&gt;&lt;/iframe&gt;
      &lt;/body&gt;
   &lt;/html&gt;
  </code></pre>
  
  <p>however, it doesn't work if I haven't log into facebook, what't the problem?
  and how to implement the same function in twitter?</p>