My code:

```
<?php

    $country = array(
                 'zh' => array( 'tw' => "Traditional Chinese"),
                 'zh' => array( 'cn' => "Simplified Chinese"),
                 'en' => "English",
                 'jp' => "Japanese"
               );

 echo $country['zh']['tw'];
 echo $country['zh']['cn'];
 echo $country['en'];
 echo $country['jp'];

```

For some reason I get this notice:

> 
> Notice: Undefined index: tw in C:\UniServerZ\www\p7.php on line 3
> 
> 
> 

And I don't see where the bug is in the code?