dave-kennedy/index.html

## index.html
<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
    </head>
    <body>
        <form>
            <p>
                <label>
                    URL: <input name="url">
                </label>
            </p>
            <p>
                Headers: <input type="button" id="add-header" value="Add">
            </p>
            <div id="headers"></div>
            <p>
                <input type="submit" value="Submit">
            </p>
        </form>
        <script>
            (function () {
                var addHeaderBtn = document.getElementById('add-header'),
                    headers = document.getElementById('headers');

                function addHeader() {
                    var row, key, value;
                    row = document.createElement('p');
                    key = document.createElement('input');
                    value = document.createElement('input');
                    key.name = 'headerKeys[]';
                    key.placeholder = 'Key';
                    value.name = 'headerValues[]';
                    value.placeholder = 'Value';
                    row.appendChild(key);
                    row.appendChild(value);
                    headers.appendChild(row);
                }

                addHeaderBtn.addEventListener('click', addHeader);
            }());
        </script>
    </body>
</html>
	<!doctype html>
	<html>
	<head>
	<meta charset="utf-8">
	</head>
	<body>
	<form>
	<p>
	<label>
	URL: <input name="url">
	</label>
	</p>
	<p>
	Headers: <input type="button" id="add-header" value="Add">
	</p>
	<div id="headers"></div>
	<p>
	<input type="submit" value="Submit">
	</p>
	</form>
	<script>
	(function () {
	var addHeaderBtn = document.getElementById('add-header'),
	headers = document.getElementById('headers');

	function addHeader() {
	var row, key, value;
	row = document.createElement('p');
	key = document.createElement('input');
	value = document.createElement('input');
	key.name = 'headerKeys[]';
	key.placeholder = 'Key';
	value.name = 'headerValues[]';
	value.placeholder = 'Value';
	row.appendChild(key);
	row.appendChild(value);
	headers.appendChild(row);
	}

	addHeaderBtn.addEventListener('click', addHeader);
	}());
	</script>
	</body>
	</html>