Uncaught TypeError: Cannot call method 'click' of null - saveDetectionSelectors

Hi, 

ckeditor gives an error on Chrome Console 

Uncaught TypeError: Cannot call method 'click' of null          plugin.js:43

and nothing appears. No Editor, No raw textarea.

On the line 43 there's this code

            $(saveDetectionSelectors).click(function () {

-----------------------here the error message -------------------------
                RemoveStorage(autoSaveKey);
            });

the HTML

<textarea cols="80" name="Text" id="HtmlEditor1" rows="80"></textarea>

<script>
CKEDITOR.replace('HtmlEditor1');
</script>

Can you help me?

Thanks