Multiple use on single page

[kiwi3685]

I am using this on pages where there are many blocks of text to be shortened. These are help texts on a configuration page. It works well, but it would be nice if when a second block of text is opened (click "more") any other already opened block was automatically closed. It would save users needing to click 'less' every time before they open a second (or more) block.

Is this possible?

Perhaps something like:
$this.parent().siblings().find(".comment").slideUp();

I realise that exact code will not work here, but the principle of using sibling elements might??