FCKEditor validation using javascript

function ValidateFCKEditor(fckEditorClientID) {

            varError = "";

            var objFCKeditor1 = document.getElementById('<%=fckNotes.ClientID%>');

           

            if (typeof (FCKeditorAPI) != undefined) {

                var oEditor = FCKeditorAPI.GetInstance(objFCKeditor1.id);

                if (oEditor.GetXHTML(true) == "") {

                    varError += "Entering text in fckeditor is mandatory.\n";

                }

                if (varError != '') {

                    alert(varError);

                    return false;

         

                }

            }

        

                return true; 

      }