title: text+variable concatenation as string inside appendChild($variable) with pure javascript
body: <p>I know zero javascript. I achieved most  of my requirements by converting &amp; combining little scripts. however at the point I described below I couldn't solve my requirement totally.</p>
  
  <p><strong>I want to print the value of the hyperlink id before my constant text also.</strong> <strong>I don't use jquery.</strong></p>
  
  <p>For example for the time being it's only writing "<em>is being replied by the time being.</em>"</p>
  
  <p>However (assume hyperlink id = 6) it should write "<strong>6</strong> <em>is being replied by the time being.</em>"</p>
  
  <p>I've read this SO Q&amp;A but I couldn't benefit from it. (<a href="https://stackoverflow.com/questions/27862951/js-how-to-concatenate-variables-inside-appendchild">JS: How to concatenate variables inside appendChild()?</a>)</p>
  
  <p><strong><a href="http://jsfiddle.net/nc43vypp/3/" rel="nofollow noreferrer">DEMO FOR THE CURRENT STATE @JSFIDDLE</a></strong></p>
  
  <p><strong>JS in body tags</strong></p>
  
  <pre><code>function reply_comment (id) {
      var LinkId = document.getElementById('parent_id');    
      LinkId.value = id;
      var message = document.createTextNode(" is being replied by the time being.");
      document.getElementById('print_id').appendChild(message);
      document.getElementById("focus_id").focus();
  }
  </code></pre>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;!-- codes given above --&gt;
  &lt;script type="text/javascript"&gt;
  ... ... ...
  &lt;/script&gt;
  &lt;!-- codes given above --&gt;
  
  &lt;!-- when clicked on the hyperlink, store the hyperlink id value (id value is an unsigned integer)  --&gt;
  &lt;!-- print the stored id from hyperlink into the value="{unsigned integer id}" part of input ( type:text and id="parent_id" )--&gt;
  &lt;!-- focus on comment form's input ( type:text and id="focus_id" )  --&gt;
  &lt;!-- print preset message between span tags ( span tag id="print_id"  ) --&gt;
  
  
  &lt;a class="rep"  href="#focus_id" onclick="reply_comment(this.id);" id="6" rel="nofollow"&gt;reply comment&lt;/a&gt;
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  &lt;span id="print_id"&gt;&lt;/span&gt;
  &lt;form&gt;
      &lt;label for="focus_id"&gt;Focus the cursor below&lt;/label&gt;
      &lt;input  type="text" id="focus_id" name="focus_id"&gt;
      &lt;label for="parent_id"&gt;Paste parent_id below&lt;/label&gt;
      &lt;input  type="text" id="parent_id" name="parent_id" value=""&gt;
  &lt;/form&gt;
  </code></pre>