Is it possible to use JavaScript to change the meta-tags of the page?

Question

If I put a div in the head and display:none, than use JavaScript to display it, will this work?

Edit:

I have stuff loaded in AJAX. And as my AJAX changes the

Answer 1

meta-tags are part of the dom and can be accessed and -i guess- changed, but search-engines (the main consumers of meta-tags) won't see the change as the javascript won't be executed. so unless you're changing a meta-tag (refresh comes to mind) which has implications in the browser, this might be of little use?