Hiding text depending on users OS

Hiding text depending on users OS

Hi,
 
I am currently working on a new project. I would like hide certain text depending on what the OS the client is using. I have this working to stop Mac users downloading software that is only meant for Windows users: <script type="text/javascript">
 $(function(){
  $('.software').click(function(e){
   if ($.client.os != "Windows"){
    e.preventDefault();
    jAlert('<strong>The Software on this CD only runs on Windows.</strong>.', 'Resources');
   }
  });
 });
</script>








 
Just wanting to know how to hide a <p class="mac"> when the page finds out that the OS is windows? All the tutorials that I have found only hide when you click a button.
 
Thanks in advance.