I jus tran your code through the validator and got 19 errors...... anyhow. your .css file does not need <style> elements in it
and on the footer should be like this:
align="center" is deprecated in xhtml, use css to center things
id must be in qoutation marks ( or not at all will technically work too but thats a bad ide) , you were missing one
html elements generally only use semicolons in inline javascript and inline css style
Code:
< a href="/" onclick="javascript:dosomething();" style="text-align:center;">test</a>