I have a div with an id of `content` and I want to get the `id` of the first level `div` elements, eg. `box1`, `box2`, `box3`. How can this be done ?

```
<div id="content">
    <div id="box1" class="box1class">
        <div>...</div>
    </div>
    <div id="box2" class="box1class">
        <div>...</div>
    </div>
    <div id="box3" class="box1class">
        <div>...</div>
    </div>
</div>

```