cairo 1.2.6

["Jamiil Abduqadir" <jalqadir gmail com>]

OS:      LINUX - DEBIAN - SARGE
lib:     CAIRO 1.2.6

I am trying to install gtkmm-2.10.x from source, for
that I need to install cairo 1.2.6, as it is a prerequiset. However
after typing './configure' I get this error message:
checking for cairo's PNG backend...
./configure: line 24784: --exists: command not found
./configure: line 24784: --exists: command not found
./configure: line 24784: --exists: command not found
configure: WARNING: Could not find libpng in the pkg-config search path
checking whether cairo's PNG backend could be enabled... no
configure: error: requested PNG backend could not be enabled

I have installed ZLIB 1.2.3, PNG 1.2.16, but I am still getting the same message, what else do I need to do?
-- 
When in doubt remember that,
"By the Guidence of God, an amateur built The Ark... and that guided by science 'they' built The Titanic!"