Implementation method of content length limit statistics of Fckeditor editor

=function(){
function FCKeditor_OnComplete()
{
var editor = ('info') ;
('OnSelectionChange', editor_keydown);
}
function editor_keydown(editor)
{
var maxLength=3; //Maximum number of input words
content= $().text();
var len= ;
var $info =$('#info');//Storage prompt information
if(len < maxLength){
.text("You can also enter "+(maxLength-len)+" word");
}
if(len == maxLength){
$("The word count reaches the upper limit");
}
if(len > maxLength){
$(" The input characters exceeds "+maxLength+" number, please change it!");
}
}
FCKeditor_OnComplete()
}