Allow letters, digits and certain characters
<p>In a form a user can input some text. In the validation php I would like to check if this text includes only letters, numbers and the allowed special characters: <code>.,:;'"/*$@#&lt;&gt;&amp;+-</code></p>

<pre><code>$pattern = '/^i';
$chars = ".,:;'\"/*$@#&lt;&gt;&amp;+-";
$newString = htmlspecialchars($chars);
if (!preg_match($pattern, $chars, $text))   $error = $error . "You can use only letters, digits and [.,:;'\"/*$@#&lt;&gt;&amp;+-]".'&lt;br&gt;';
</code></pre>

<p>The <code>$error</code> variable is sent back to the page with the form and displayed there.</p>

<p>Am I using the wrong pattern? No matter what I type in the input box I get the error.</p>
