Hello everyone, I get the following error when I try to view a picture in black and white in chapter 7:

Fatal error: Call to undefined function: imagefilter() in D:\Websites\PHPBook\chapter 07\modifyimage.php on line 32

My question is...does the imagefilter()function only run on php5? Is this the source of my error?

I am currently running php 4.3.6.

Thanks for your help.

Just had the same problem. I understand that imagefilter() function is not available until PHP5.