function validateSubscribeForm() {
    el = document.getElementById('signup_email');
    if (el.value == "" || el.value == "email address") {
      alert("Please enter your email address");
      el.focus();
      return false;
    }

    if (isEmail(el.value) == false) {
      alert("Please enter a valid email address (e.g. yourname@yourcompany.com.au)");
      el.select();
      return false;
    }

    // remove default content if user hasn't entered first name
    el = document.getElementById('signup_first_name');
    if (el.value == "your name") {
      el.value = "";
    }

    return true;
  }

  function isEmail(string) {
    return (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
  }