 <p>When you would like to change the <code>$n</code>. character to <code>$something</code>:</p> <pre><code>$_SESSION['b1'][$n] = $something; </code></pre> <p>In your case:</p> <pre><code>$_SESSION['b1'][1] = $_SESSION['word'][0]; </code></pre> <p>Details:</p> <p><a href="http://www.php.net/manual/en/language.types.string.php#language.types.string.substr" rel="nofollow">http://www.php.net/manual/en/language.types.string.php#language.types.string.substr</a></p>