function doVoucher(f) {
  if (f && f.elements["vouchers"]) {
    var fo = f.elements["vouchers"];
    var qs = "";
    for (var i = 0; i < fo.length; i++) {
      if (fo[i] && fo[i].checked) {
        qs += "vouchers=" + escape(fo[i].value) + "&";
      }
    }
    if (qs) {

      //uncomment the line below for soupermail
      //var uri = "/cgi-bin/soupermail.pl?SoupermailConf=/vouchers/v.con&" + qs;

      //uncomment the line below for pure javascript
      var uri = "vouchers/list.htm?" + qs;

      if (!navigator.voucherWin || navigator.voucherWin.closed) {
        navigator.voucherWin = window.open(uri, "vouchers", "width=430,height=500,scrollbars=yes,statusbar=no,location=no,menubar=yes,directory=no");
      } else {
        navigator.voucherWin.location = uri;
      }
    }
  }
  return false;
}