We　propose　a　protocol　to　generate　a　Greenberger-Horne-Zeilinger　(GHZ)　state　andWstate　by　using　simple　linear　elements　and　quantum　nondemolition　detectors　(QNDs).　With　the　help　of　cross-Kerr　nonlinearity,　our　protocol　can　generate　the　intended　states　with　only　one　setup,　and　the　probability　of　getting　a　W　state　is　greatly　increased　when　compared　with　previous　schemes　[Phys.　Rev.　A　75　(2007)　044301].　Also,　our　proposed　protocol　is　realizable　in　experiments.