title: CKEditor : Remove default text "image preview" in box using CKEditor
body: <p>firstly thanks in advance.
  in CKEditor when i click on image tab in tool box , the image properties window open, in this window , we upload the image and also image preview box is there , but when the "image properties " windows open in the "image preview" box there is some text like show in this link 
  <a href="http://ckeditor.com/demo" rel="nofollow">http://ckeditor.com/demo</a> but i want to remove the default text in "image preview" box at initialize time. how can we done ?</p>