configure: error: can't find X includes

[Nonno Bassotto]

I was trying to create a deb package for KtabEdit
http://kguitartmp.sourceforge.net/
but the command "auto-apt run ./configure" ends with the line

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

I don't know what I should do now. Can anybody help me? Please note that this is my first try to make a deb package, so try to explain in a simple way.

[tonyr]

The headers are in the development libraries. Install package libx11-dev and try
again. You may run into other configure failures like this. The development
libraries you need may be listed in a document somewhere in the source tree, maybe
README or INSTALL, or you may have to discover what you need as configure
reports failures.

[Nonno Bassotto]

after installing xlibs-dev this step goes smoothly, but now it stops at

checking for Qt... configure: error: Qt (>= Qt 3.2) (headers and libraries) not found. Please check your installation!

I have tried to install libqt3-mt-dev but I get the error

libqt3-mt-dev:
Depends on: libfreetype6-dev but it is not going to be installed
Depends on: libxft-dev but it is not going to be installed

(the translation is mine). The same error if I try with libqt4-dev. This must be related to the fact that I installed new libraries to get better fonts, following an howto on this forum. I don't want to screw up my installation to compile this (I already have to remove lots of things). I think I will do without.
Thank you for your help