function toggle(tag) {
  var answer = document.getElementById(tag);
  //var image = document.getElementById('image'+tag);
  if (answer.style.display == 'block') {
    //image.src = 'minus.gif'; //This is where you would change the image.
    answer.style.display = 'none';
  }
  else {
    //image.src = 'plus.gif'; //Image changing.
    answer.style.display = 'block';
  }
}