title: select CSS URL dynamically via Javascript
body: <p>Is there a way to add a <code>&lt;link rel="stylesheet" type="text/css"&gt;</code> with the URL dynamically-selected based on some Javascript expression evaluation?</p>
  
  <p>(without using jQuery or other external library -- I want to avoid dependencies on external libraries.)</p>
  
  <p>In particular I want to run some Javascript during or as a result of pageload, rather than at a later date, but I do want to make sure the CSS that has been replaced or added gets loaded as a result of running that Javascript.</p>