Can't find X includes???

Hello SuSE folkz, I was trying to install unixODBC from the tar ball on SuSE8.1. During configuration it exits with error: Can't find X includes. Please check your installation and add the correct path. The question is where and in what system config file I have to add the correct path /usr/X11R6/include to overcome this issue. Interesting enough, I didn't have this problem on SuSE8.0 and 7.3 Many thanks in advance for any help. Alex -- Microsoft Windows users should be covered under the Americans with Disabilities Act!!! Try Linux and you'll understand why...