title: Tried to register widget with id but that id is already registered
body: <p>I have two buttons and would like to load a different custom template widget into a div depending on which button is pressed.  It works fine the first click, but then comes up with the subject error when either of the buttons is clicked again. I've got this very simplified example to try and get the concept working</p>
  
  <p>my template code (there are two very similar to this):</p>
  
  <pre><code>define([
    "dojo/_base/declare",
    "dijit/_WidgetBase",
    "dijit/_TemplatedMixin",
    "dojo/text!Templates/Person.htm"
  ], function (declare, _WidgetBase, _TemplatedMixin, personTpl) {
      return declare([_WidgetBase, _TemplatedMixin], {
          templateString: personTpl
      });
  });
  </code></pre>
  
  <p>my template (there are two very similar to this):</p>
  
  <pre><code>&lt;div&gt;
    &lt;p&gt;Bob Jones&lt;/p&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Main page:</p>
  
  <pre><code> &lt;body class="claro"&gt;
  
      &lt;script&gt;
          require([
          "dijit/form/Button", 
          "Templates/Person", "Templates/Person2", "dojo/domReady!"
       ], function (Button, Person, Person2) {
           var Button1 = new Button({
               label: "Person1",
               onClick: function () {
                   var p = new Person({}, "page");//error occurs here after a button has been pressed once
               }
           }, "btnPerson1").startup();
  
           var Button2 = new Button({
               label: "Person2",
               onClick: function () {
                   var p2 = new Person2({}, "page"); //error occurs here after a button has been pressed once
               }
           }, "btnPerson2").startup();
       });
      &lt;/script&gt;
      &lt;button id="btnPerson1" type="button"&gt;&lt;/button&gt;
      &lt;button id="btnPerson2" type="button"&gt;&lt;/button&gt;
      &lt;div id="page"&gt;&lt;/div&gt;
    &lt;/body&gt;
  </code></pre>
  
  <p>Thanks for any ideas</p>