Stock firmware from Samfirmware, boot into download mode, flash with Odin. Can't boot into download mode ? Try a jig. Still can't boot into download mode or boot the phone at all ? Service centre or local mobile repair shop.
If it's important enough to cause you grief if it's lost, back it up. No excuses
Trolling for thanks is lame
Does Samsung's auto-brightness implementation crap drive you to self-harm ? A solution !
Failure to search is the leading cause of male impotence on XDA
If you don't know how to recover if things go wrong, what are you doing flashing custom roms ?