[CentOS] phpmyadmin on centos 4

hi there,

i have a centos box with phpmyadmin installed, but i don't remember how i 
installed phpmyadmin 2.7.0-pl2.  now i want to upgrade it with yum, but i 
don't find any phpmyadmin on my centos box.  i tried:

rpm -qa | grep phpmyadmi, but found nothing.

is there an easy way to upgrade phpmyadmin?

thanks,
T. Hiep