function openLink() {
  if (document.forms[0].site.value != "") {
    location.href = document.forms[0].site.value;
  }
  else {
    alert("Please choose a product");
  }
}

function openLinkWin() {
  if (document.forms[0].site.value != "") {
    window.open(document.forms[0].site.value);
  }
  else {
    alert("Please choose a product");
  }
}