i have a select box which is really simple but it keeps outputting empty options which i don't have these options. why is this?

```
<form id ="orderby" action="" method="post">
    <select name="orderby"style="float:right;">
        <option selected="true" style="display:none;">choose view order</option>
        <option value="ASC" >Ascending<option>
        <option value="DESC">Descending<option>
    </select> 
    <input type="submit" value="Arrange" />
</form>

```