var original_label_color;
var original_color;
var new_color = 'grey';

function set_anonymous(checkbox) {
  label_element = document.getElementById('new_review_reviewer_label');
  text_element = document.getElementById('new_review_reviewer');

  if (checkbox.checked) {
    original_label_color = label_element.style.color;
    original_color = text_element.style.color;
    label_element.style.color = new_color;
    text_element.style.color = new_color;
    text_element.value = '';
    text_element.disabled = true;
  } else {
    label_element.style.color = original_label_color;
    text_element.style.color = original_color;
    text_element.disabled = false;
  }
}