var astro_domain = "astro.swin.edu.au";
  var swin_domain = "swin.edu.au";
  var groupwise_domain = "swin.edu.au";

  function custom_email(uname, domain, name)
  {
    if (name == "")
    {
      name = uname+"@"+domain;
    }

    var sb_recipient = uname + "@" + domain;
    var sb_url = "mailto:" + sb_recipient
    document.write(name.link(sb_url));
  }

  function astro_email(uname, name)
  {
    custom_email(uname, astro_domain, name);
  }

  function swin_email(uname, name)
  {
    custom_email(uname, swin_domain, name);
  }

  function groupwise_email(uname, name)
  {
    custom_email(uname, groupwise_domain, name);
  }