var popup = null;
var emailIsClear = false;

function clearEmail() {
 if(!emailIsClear) {
    emailIsClear = true;
    document.getElementById('email').value = '';
  }
}

function subscribe(theForm) {
  popup = window.open('', 'popup', 'scrollbars=no,width=550,height=520');
  var aForm = document.getElementById('email-submit');
  aForm.target = 'popup';
  aForm.submit();
}