gistfile1.html

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.js"></script><script type="text/javascript">// Requires that JQuery also be in scope
function findInputList(button) {
  var mainDiv = $(button).parent();
  while ( !mainDiv.hasClass('inputList') ) {
    mainDiv = $(mainDiv).parent();
  }
  return mainDiv;
}

function findItems(button) {
  return $('.inputListItem', findInputList(button));
}

function addItem(button) {
  var count = $(':hidden', findInputList(button))[0];
  var items = findItems(button);
  var item = $(items[items.length-1]);
  var newItem = item.clone(true);
  var i;

  // Increment counter
  $(count).val(parseInt($(count).val())+1);

  // We have to change the raw html because IE doesn't allow the
  // name field to be changed.
  newItem.html(newItem.html().replace(/fval\[(\d+\.)*(\d+)\.(\d+)\]/g,
    function(a, b, c, d) {
      var newC = parseInt(c)+1;
      return a.replace(/\d+\.\d+\]/, newC+'.'+d+']');
    }
  ));
  newItem.appendTo(item.parent());

  // Copy the values of all children that had the name attribute set.
  // The direct html insertion does not preserve the most current
  // values.  It only preserves default values, so if we want values
  // copied, we have to use an approach like this.
  var items2 = findItems(button);
  var newLast = $(items2[items2.length-1]);
  var c1 = $('[name]', item);
  var c2 = $('[name]', newLast);
  if ( c1.length == c2.length ) {
    for ( i = 0; i < c1.length; i++ ) {
      $(c2[i]).val($(c1[i]).val());
    }
  }
}

function removeItem(button) {
  var items = findItems(button);
  if ( items.length > 1 ) {
    var count = $(':hidden', findInputList(button))[0];
    var item = $(items[items.length-1]);
    item.remove();

    // Decrement counter
    $(count).val(parseInt($(count).val())-1);
  } else {
    alert('Cannot remove any more rows');
  }
}
</script><style type="text/css">input {display: block;}
.digestive-error-list {
    color: white;
    background-color: rgb(100, 0, 0);
}</style><h1>Enter the names of places and some tags</h1><form enctype="application/x-www-form-urlencoded" method="POST" action="/"><div class="inputList"><div><input type="button" onclick="alert('&lt;label for=&quot;place-form-fval[0]&quot; class=&quot;digestive-label&quot;&gt;Name&lt;/label&gt;&lt;input type=&quot;text&quot; name=&quot;place-form-fval[0]&quot; id=&quot;place-form-fval[0]&quot; value=&quot;&quot; class=&quot;digestive-input&quot; /&gt;&lt;div class=&quot;inputList&quot;&gt;&lt;div&gt;&lt;input type=&quot;button&quot; onclick=&quot;alert(&#39;&amp;lt;input type=&amp;quot;text&amp;quot; name=&amp;quot;place-form-fval[1]&amp;quot; id=&amp;quot;place-form-fval[1]&amp;quot; value=&amp;quot;&amp;quot; class=&amp;quot;digestive-input&amp;quot; /&amp;gt;&#39;); return false;&quot; value=&quot;Add Item&quot; /&gt;&lt;input type=&quot;button&quot; onclick=&quot;removeItem(this); return false;&quot; value=&quot;Remove Item&quot; /&gt;&lt;/div&gt;&lt;input type=&quot;hidden&quot; name=&quot;place-form-fval[1]&quot; id=&quot;place-form-fval[1]&quot; value=&quot;1&quot; class=&quot;digestive-input&quot; /&gt;&lt;div class=&quot;inputListItem&quot;&gt;&lt;input type=&quot;text&quot; name=&quot;place-form-fval[1.0.0]&quot; id=&quot;place-form-fval[1.0.0]&quot; value=&quot;&quot; class=&quot;digestive-input&quot; /&gt;&lt;/div&gt;&lt;/div&gt;'); return false;" value="Add Item" /><input type="button" onclick="removeItem(this); return false;" value="Remove Item" /></div><input type="hidden" name="place-form-fval[0]" id="place-form-fval[0]" value="1" class="digestive-input" /><div class="inputListItem"><label for="place-form-fval[0.0.0]" class="digestive-label">Name</label><input type="text" name="place-form-fval[0.0.0]" id="place-form-fval[0.0.0]" value="" class="digestive-input" /><div class="inputList"><div><input type="button" onclick="alert('&lt;input type=&quot;text&quot; name=&quot;place-form-fval[0.0.1]&quot; id=&quot;place-form-fval[0.0.1]&quot; value=&quot;&quot; class=&quot;digestive-input&quot; /&gt;'); return false;" value="Add Item" /><input type="button" onclick="removeItem(this); return false;" value="Remove Item" /></div><input type="hidden" name="place-form-fval[0.0.1]" id="place-form-fval[0.0.1]" value="1" class="digestive-input" /><div class="inputListItem"><input type="text" name="place-form-fval[0.0.1.0.0]" id="place-form-fval[0.0.1.0.0]" value="" class="digestive-input" /></div></div></div></div><input type="submit" value="Submit" /></form>