HTML5 slider Input
http://jsfiddle.net/Xjxe6/
<form>
<input type="range" name="amountRange" min="0" max="20" value="0" oninput="this.form.amountInput.value=this.value" />
<input type="number" name="amountInput" min="0" max="20" value="0" oninput="this.form.amountRange.value=this.value" />
</form>