gd library for php5 under ES4

[Doug Fulton <dougfulton comcast net>]

I am trying to use the php gd library (for imagecreate, etc).  I  
tried installing php-gd via webmin (which in turn, I see, uses  
up2date), but get the following error in the apache error log when  
restarting:
PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib/ 
php4/gd.so' - /usr/lib/php4/gd.so: undefined symbol: empty_string in  
Unknown on line 0

I don't know if the problem is that php-gd is a php4 library or there  
is something else that I need to install or do.  I saw something  
about php5-gd, but webmin/up2date can't find anything by this name.

I have searched for a bit on this without joy; any guidance is  
appreciated.  (I am not a system administrator by training, but am a  
longtime Unix programmer, so I can handle reasonably low level  
instructions, if necessary.)

Thanks in advance,
Doug