title: Load js from external site on fly
body: <p>I want to load JS code from external site when user click on button. For example:</p>
  
  <pre><code> &lt;button onclick="LoadJSFromURL('facebook.com/blablabla')" /&gt;
  </code></pre>
  
  <p>and when user press button we attach new script to the document:</p>
  
  <pre><code>&lt;script&gt; Share.WorkUrl="http://MySite.com"; Share.UserId=5 &lt;/script&gt; &lt;script src="http://Facebookcom/blabalbal" &gt;&lt;/script&gt;
  </code></pre>
  
  <p>and then we must execute this script. Is it real?</p>