lamer,
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<div>
<label id="city">
<span id="your_city"></span>
</label>
<input type="text">
</div>
<script type="text/javascript">
var city = document.getElementById('city');
var your_city = document.getElementById('your_city');
city.insertBefore( document.createTextNode('City'),your_city)
//city.appendChild(document.createTextNode('City'));
your_city.innerHTML = 'Your City';
</script>
</body>
</html>