Setting Metatags Problem

Setting Metatags Problem

Hi,

i want to dynamically update the meta Tag "keywords" and "desciption".
I know or think, that the search-engines cant read the tags, when
i change them via $(document).ready.

I have tried:
  1. $(document).ready(function(){
  2. $('meta[name=keywords]').attr('content', 'Test1,Test2,Test4');
    $('meta[name=description]').attr('content', 'Test Description');
    )};

But when i look into the source-code, there are no changes...

Updating the "page-title-attribute" works!
document.title = 'Test';

Any idea ?