gistfile1.js

// I was bored.
// Sorry :(

function d(id){ return document.getElementById(id); }
window.onload = function(){
  var email_only = d('email_only'),
      mail_only = d('mail_only'),
      phone_only = d('phone_only');
  mail_only.style.display = phone_only.style.display = 'none';
  d('contact_us_stype_email').onclick = function () {
    email_only.style.display = 'block';
    mail_only.style.display = phone_only.style.display = 'none';
  };
  d('contact_us_stype_mail').onclick = function () {
    mail_only.style.display = 'block';
    email_only.style.display = phone_only.style.display = 'none';
  };
  d('contact_us_stype_phone').onclick =  function () {
    phone_only.style.display = 'block';
    email_only.style.display = mail_only.style.display = 'none';
  };
};