using javascript api, error: FCKeditorAPI is not defined

<?
   $oFCKeditor = new FCKeditor('FCKeditor1') ;
   $oFCKeditor->BasePath = 'library/fckeditor/';
   $oFCKeditor->ToolbarSet='Basic';
   $oFCKeditor->Value = stripslashes($template->email_body);
   $oFCKeditor->Create();
?>

   <script type="text/javascript">
   var oEditor = FCKeditorAPI.GetInstance('FCKeditor1');
   var oEditor = window.parent.InnerDialogLoaded().FCK ;
   oFCKeditor.InsertHTML='hello world';
   </script>

FCKeditorAPI is not defined
[Break on this error] var oEditor = FCKeditorAPI.GetInstance('FCKeditor1');