where is the gtk+ in suse?

darkpower

when I tried to install gaim0.68, such error happend:
checking for pkg-config... (cached) /usr/bin/pkg-config
checking for GTK+ - version >= 2.0.0... no
*** Could not run GTK+ test program, checking why...
*** The test program failed to compile or link. See the file config.log for the
*** exact error that occured. This usually means GTK+ is incorrectly installed.
configure: error:
*** GTK+ 2.0 is required to build Gaim; please make sure you have the GTK+
*** development headers installed. The latest version of GTK+ is
*** always available at http://www.gtk.org/.

there's gtk+ in my system, I think. But why the configure script can not find it?
can someone tell me how to configure.