installing qmake

I guys, i'm trying to configure qmake on Linux Mandrake 9.1. I have a proyect in qt-designer
and i wanth to use qmake to build my Makefile for the proyect. But when i do the

qmake -o Makefile mi_proyect.pro

i recive a message like "can't find the mkespecs for youre plataform even after trying
/usr/lib/qt3 "

So i read the documentation of qmake and it says that i must set the QMAKESPEC enviroment variable and especify wich distro and compiler to use. so i did

QMAKESPEC=qws/linux-x86-g++
export QMAKESPEC
but didn't work, so i try

QMAKESPEC=qws/linux-g++
export QMAKESPEC

because in $QTDIR/mkspecs/ apears linux-g++
but the same result, didn't worked.

So any of you have an idea about wath i'm doing wrong...??

xDrack