well the start command for xfce is xfwm4 and it does not run...so i just did xephwm5 Xephyr under chroot and it gave me the black window with the control back to dashboard..so xephyr was running for sure..just when i start xfwm4 the window would close..

http://www.xfce.org/documentation/4.2/manuals/xfwm4