why an i getting this qt error when trying to compile a qt program?

i have qt2 and qt3 installed

... [compiling statements] ...

checking for extra includes... no
checking for extra libs... no
checking for libz... -lz
checking for libpng... -lpng -lz -lm
checking for libjpeg6b... no
checking for libjpeg... -ljpeg
checking for Qt... libraries /usr/lib/qt3, headers /usr/include/qt3 using -mt
checking for moc... not found
configure: error: No Qt meta object compiler (moc) found!
Please check whether you installed Qt correctly.
You need to have a running moc binary.
configure tried to run and the test didn't
succeed. If configure shouldn't have tried this one, set
the environment variable MOC to the right one before running