title: Creating a custom popup with Tinymce
body: <p>Below is the code for my Tinymce textarea</p>
  
  <pre><code>    tinymce.init({
          selector: "textarea",
          height : 350,
              plugins: [
                      "link image lists preview anchor"
              ],
          toolbar: " image bold italic | formatselect | undo redo | cut copy paste | bullist numlist | undo redo | link unlink dummyimg | preview",
          menubar: false,
          toolbar_items_size: 'small',
          setup : function(ed) {
          // Add a custom button
          ed.addButton('dummyimg', {
              title : 'Add image',
              image : 'resources/images/img.jpg',
              onclick : function() {
                  if($('#imageupload').val()){
                    ed.focus();
                    ed.selection.setContent('&lt;img src="&lt;%=strWebhost%&gt;/news_cms/resources/images/dummyimg.jpg" /&gt;');
                  } else{
                    alert("Please select an image.");
                  }
  
                  }
              });
          },
          onchange_callback: function(editor) {
              tinyMCE.triggerSave();
              $("#" + editor.id).valid();
          }
     });
  </code></pre>
  
  <p>I have added a custom button called <code>dummyimg</code> which adds a predefined image into the tinymce container. My requirement is, i need a pop window like the one shown below which enables me to add only a image <code>title</code> using the custom button.</p>
  
  <p><img src="https://i.stack.imgur.com/kLj9x.png" alt="enter image description here"></p>
  
  <p>Thanks in advance.</p>