i need some help to change FCK plugins for use in CKeditor

function FormatText() {
  var oEditor = FCKeditorAPI.GetInstance(FCK.Name) ;
     if ( oEditor.EditMode == FCK_EDITMODE_WYSIWYG )
   {
  var temps = new Array();
  var sec = oEditor.EditorDocument.selection.createRange();
  var tmpText = sec.text;
  var isPart = tmpText != null && tmpText.trim().length > 0;
  isPart = false; 
  if (!isPart) {
    var imgs = oEditor.EditorDocument.images;
    if (imgs != null && imgs.length > 0) {
      for (j = 0; j < imgs.length; j++) {
        var t = document.createElement("IMG");
        t.alt = imgs[j].alt;
        t.src = imgs[j].src;
        t.width = imgs[j].width;
        t.height = imgs[j].height;
        t.align = imgs[j].align;
        temps[temps.length] = t;
      }
      var formatImgCount = 0;
      for (j = 0; j < imgs.length;) {
        imgs[j].outerHTML = "#FormatImgID_" + formatImgCount + "#";
        formatImgCount++;
      }
    }
   var html = processFormatText(oEditor.EditorDocument.body.innerText);
    if (temps != null && temps.length > 0) {
      for (j = 0; j < temps.length; j++) {
        var imghtml = "<img src=\"" + temps[j].src + "\" alt=\"" + temps[j].alt + "\" width=\"" + temps[j].width + "\" height=\"" + temps[j].height + "\" align=\"" + temps[j].align + "\">";
        html = html.replace("#FormatImgID_" + j + "#", imghtml);
      }
    }
    oEditor.SetHTML(html);
  } else {
   var html = processFormatText(tmpText);
      sec.pasteHTML(html);
  }
  }
  else
  alert( 'wrong mode！' ) ;
}