title: Insert in string AS3
body: <p>I need to insert string in another string in specific index. </p>
  
  <pre><code>var str1:String = "A";
  
  var str2:String = "LoremIpsum";
  </code></pre>
  
  <p>I need <code>str2</code> to be <code>"LoremAIpsum"</code>, insert <code>str1</code> in index 5 in <code>str2</code>.
  Thanks.</p>