imagecreatefrompng() from URL Wrong!

Hello php4beta,

  I use imagecreatefrompng() open file in my localhost;
  **************************************************
  imagecreatefrompng("/home/httpd/html/powered.png")
  **************************************************
  It can be work, when I use
  **************************************************
  imagecreatefrompng("http://localhost/powered.png")
  **************************************************
  It return:

<font color=ff0000><br>
<b>Warning</b>:  ImageCreateFromPng: Unable to open http://localhost/poweredby.png for reading in <b>/home/httpd/html/i.php3</b> on line <b>3</b><br>
</font><font color=ff0000><br>
<b>Warning</b>:  Supplied argument is not a valid Image resource in <b>/home/httpd/html/i.php3</b> on line <b>4</b><br>
</font><font color=ff0000><br>
<b>Warning</b>:  Supplied argument is not a valid Image resource in <b>/home/httpd/html/i.php3</b> on line <b>5</b><br>
</font>

What's wrong with me ?

Sorry for my english so poor!

-- 
Best regards,
 php                          mailto:[email protected]