arm-llinux-gcc cross compile

["Mike Gilorma" <phatbeatsboy hotmail com>]

I'm trying to develop an application to run on a pxa-255 based system, so I 
need to use a cross complier.  When I try to cross compile, I get an error 
message that says "gtk/gtk.h: No such file or directory."  The test program 
I have written complies fine normally, and I have used the cross compiler 
successfully before, any ideas what I might try?