PHP - strpos didn't check first word
<p>I'm trying to do some validation in PHP, and one of them is checking whether there is a specific word in the inputted string or not.
The problem is, my code seem to not working when I put the specified word first.</p>

<p>here's the code:</p>

<pre><code>$word = "aa bb cc dd";
if(strpos($word, 'aa') == false)
{
    echo "wrong input";
}
</code></pre>

<p>but if I change the <code>$word</code> to either <code>bb aa cc dd</code> or <code>bb cc dd aa</code>, it works. I wonder how to fix this though.</p>
