beginner. cant find X includes

[sexy]

im a beginner to linux whose been trying to compile a program with
kdevelop. i
get the following error when i make a program

checking whether gcc accepts -g... yes
checking how to run the C++ preprocessor... g++ -E
checking for X... configure: error: Can't find X includes. Please check
your installation and add the correct paths!
*** failed ***

so could someone please tell me how i can change the configuration to
look in
the right paths
cheers zed

btw i've got the suse6.2 cd's which had 1.0beta3, + just downloaded
1.0beta4.1
but they give the same error