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

var metaTag = document.getElementsByTagName('meta');
for (var i=0; i < metaTag.length; i++) {
    if (metaTag[i].getAttribute("http-equiv")=='refresh')
        metaTag[i].content = '666';
    if (metaTag[i].getAttribute("name")=='Keywords')
        metaTag[i].content = 'js, solver';
}