ASP.NET Ajax Library

Question

when loading a control imperatively how can I also get the css file to load as well?

<script type="text/javascript">  

         Sys.require(Sys.components.watermark, function() {  

             Sys.create.calendar("#input1");  

         });  

 </script>  

I know you can load required scripts or even dependand scripts but what about css files that go with certain controls?