How to convert from from multiple-dimension array to one-dimension array?
<p>I have the following array returned by my script.</p>

<pre><code>Array
(
    [0] =&gt; Array
        (
            [id] =&gt; 67
        )

    [1] =&gt; Array
        (
            [id] =&gt; 68
        )

    [2] =&gt; Array
        (
            [id] =&gt; 69
        )

    [3] =&gt; Array
        (
            [id] =&gt; 70
        )

)
</code></pre>

<p>How can I convert it to:</p>

<pre><code>Array
(
    [0] =&gt; 67

    [1] =&gt; 68

    [2] =&gt; 69

    [3] =&gt; 70
)
</code></pre>

<p>I'm only interested in the IDs returned.</p>
