Edit FCKEditor code to work with CKEditor

// Preview
  previewBlog: function()
  {
    var bind = this;
    var previewPane = $('entry_preview');
    var mainPane = $('entry_main');
    var previewElement = $('previewpane');
    var FCKInstance = FCKeditorAPI.GetInstance('blogentry_body');
    
    // Ajax
    var bind = this;
    var request = new Request({
      'method' : 'post',
      'url' : this.options.ajaxURL,
      'data' : {
        'task' : 'previewblog',
        'blogentry_title' : document.blogform.blogentry_title.value,
        'blogentry_body' : FCKInstance.GetHTML(),
        'blogentry_blogentrycat_id' : ( document.blogform.blogentry_blogentrycat_id ? document.blogform.blogentry_blogentrycat_id.value : 0 )
      },
      'onComplete':function(responseText)
      {
        previewElement.empty();
        previewElement.innerHTML = responseText;
        
        var tmpHTML = previewElement.getElement('.seBlogEntry').innerHTML;
        previewElement.innerHTML = tmpHTML + '<br />';
        
        TB_show(bind.Base.Language.Translate(1500067), '#TB_inline?height=400&width=600&inlineId=entry_preview', '', '../images/trans.gif');
      }
    });
    
    request.send();
  },