how to install QT on Ubuntu?

[waxwings]

Hallo,

i've been trying to install QT4.5.2 on Ubuntu9.04. after input ./configure, i got the error message

usr/local/qt/include/QtCore/../../src/corelib/global/qglobal.h:62:28: error: QtCore/qconfig.h: No such file or directory
make: *** [project.o] Error 1

usr/local/qt/include/QtCore/../../src/corelib/global/qglobal.h:62:28: error: QtCore/qconfig.h: No such file or directory
make: *** [project.o] Error 1

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has anyone an idea where the problem is? thanks.