LinuxQuestions.org - X include files

Hi,

I have been trying to compile a package I have and I was faced with the following error while running the configure script:

Code:

checking for vsnprintf... yes

checking for snprintf... yes

checking for X... configure: error: Can't find X includes. Please check your installation and add the correct paths!

[mgreen@0-15-c5-6a-75-b7 kprayertime]$

Where are these X include files? and how may I tell the configure script about them?
I am on a Fedora 8 box.
Thanks,

max