Deleting cookies with javascript?

Hi

I am working on a .net basket where I save the info for the products in the basket etc in a cookie.

Now I have an html button on the basket page where I want to be able to delete the product (Cookie).

I am using

<script type="text/javascript">
        function delete_cookie ( cookie_name )
        {
            expires = Now();
            document.cookie = cookie_Name+"= ;expires="+expires.toGMTString();
        }

    </script>

Code (markup):

But I get an error that says the cookie is not delcared? But it does exist because I retrive the name of the cookie when looping through the cookie list.

What am I doing wrong here?

 

Javascript is case sensitive, so it should work if you change cookie_Name to cookie_name