php QR code - Shows text instead of image
<p>I'm trying to get a QR code working. </p>

<p>when i run it like: </p>

<pre><code>&lt;?php
include 'phpqrcode/qrlib.php';

QRcode::png('hwllo');
?&gt;
</code></pre>

<p>it's working. However if i run it with some other php code </p>

<pre><code>&lt;?php
include 'phpqrcode/qrlib.php';

echo 'Hello world';

QRcode::png('hwllo');
?&gt;
</code></pre>

<p>it displays: </p>

<p>Hello world‰PNG  IHDRWWKK/PLTEÿÿÿUÂÓ~²IDAT8ÍÒ1„ Ðo(èô&amp;^ƒŽ+­0r¸× ávÆYbÖÝ-phêM÷ùð´ˆLHD‘qá‚XÁZ'ç“Ë › š¶H CX™¾ª.ù­ú½¥êsUT&lt;±eqhÖy|áÓÃ;š¶¼wž3d„D8÷ŠÈ—*ÀøÌEEÆgãL<code>\ú4a_ÀZ§UŠãúw¶35l|ìër_Lë•¡ê’ßQœçgÍü#Ãò¡IEND®B</code>‚</p>
