function check_fields(f) {
  if (f.naam.value.length == 0) {
    alert("Bitte, tragen Sie Ihren Name ein.");
    f.naam.select();
    return(false);
    }
  if (f.email.value.length == 0) {
    alert("Bitte, tragen Sie Ihre E-mailadresse ein.");
    f.email.select();
    return(false);
    }
  setCookie("Skylge_UsrName",f.naam.value);
  setCookie("Skylge_UsrEmail",f.email.value);
  return(true);
}

function btn_okClick(f) {
  if (check_fields(f) == true) {
     setCookie("Skylge_UsrMailingList","1");
     f.submit();
  }
}

function show_discount() {
	window.open("d_crew_discount.html","Discount","scrollbars=no,width=500,height=275");
}

function show_boeken() {
	window.open("d_boekeninfo.html","Buchen","scrollbars=yes,width=500,height=275");
}

function show_aanboord() {
	window.open("d_aanboord.html","Anbord","scrollbars=yes");
}