title: How to use onKeyUp function in ckeditor
body: <p>I use CKeditor in my page, and tried to count the remaining characters on KeyUp method.</p>
  
  <p>Here's is my code</p>
  
  <p>HTML</p>
  
  <pre><code>&lt;div class="row"&gt;
    &lt;div class="col-xs-12 col-sm-6 inputBlock textareaRegion"&gt;
    &lt;div id="editor1" class="textarea"&gt;&lt;/div&gt;
    &lt;label class="showLabel"&gt;Comments&lt;/label&gt;&lt;div class="maxlengthCountDiv"&gt;Remaining character length:&lt;span class="maxlengthCount"&gt;&lt;/span&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="row"&gt;
    &lt;div class="col-xs-12 col-sm-6 inputBlock textareaRegion"&gt;
    &lt;div id="editor2" class="textarea"&gt;&lt;/div&gt;
    &lt;label class="showLabel"&gt;Comments&lt;/label&gt;&lt;div class="maxlengthCountDiv"&gt;Remaining character length:&lt;span class="maxlengthCount"&gt;&lt;/span&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And replacing it using CKeditor also setting toolbar </p>
  
  <pre><code>  CKEDITOR.replace( 'editor1' );
    CKEDITOR.replace( 'editor2' );
  
  CKEDITOR.config.toolbar = [
         ['Styles','Format','Font','FontSize'],
         ['Bold','Italic','Underline','StrikeThrough','-','Undo','Redo','-','Cut','Copy','Paste','Find','Replace','-'],
         ['NumberedList','BulletedList'],
      ] ;
  </code></pre>
  
  <p>javascript code</p>
  
  <pre><code>$(document).on("keyup", ".textarea", function (event) {
          var textCount="";
          var textLimit = 1500;
          var deleteKey = 46;
          var backspaceKey = 8;
          var keyCode = event.keyCode;
          if (keyCode === deleteKey || keyCode === backspaceKey){
              var str = $(this).text();
              var currentCount = parseInt($(this).parents('.textareaRegion').find('.maxlengthCountDiv .maxlengthCount').text());
              if(currentCount &lt; textLimit){
                  textCount = currentCount + 1;
                  $(this).parents('.textareaRegion').find('.maxlengthCountDiv .maxlengthCount').empty().html(textCount);
              }
  
              return true;
          }
          else{
              var str = $(this).text();
              if (str.length &gt;= 1500)
              {
                  return false;
              }
              else{
                  textCount = textLimit - str.length;
                  $(this).parents('.textareaRegion').find('.maxlengthCountDiv .maxlengthCount').empty().html(textCount);
              }
          }
      });
  </code></pre>
  
  <p>The KeyUp function is not fired.how to fix this issue ?</p>