Phone [Q]cwm light blue screen

last day i installed cwm on my galaxy ace gt-s5830 first time it worked but second time light blue screen come up i can enter myrom but
i cant do rom flash with odin because when i plug phone in the downloading mode computer says USB device not recognized

i think in the recovery mode first option is reboot system now

i clicked home button and phone restarted

Please help

sorry for my bad english