helo i already set environment variables in /etc/.profile as shown below

QTDIR=/usr/local/qt
PATH=$QTDIR/bin:$PATH
MANPATH=$QTDIR/man/doc:$MANPATH
LD_LIBRARY_PATH=$QTDIR/lib:$LD_LIBRARY_PATH
after writing this data in .profile
i write on terminal
#export QTDIR PATH MANPATH LD_LIBRARY_PATH
but my problem is not solved
Thx n Regards,
Amit