TKOF STARTED; THEN ABORTED; WITHOUT CLRNC.

Narrative

'OK; YOUR LEG; LET'S GO.' I COMPLETED THE CHKLIST AND THE CAPT ADVANCED THE PWR LEVERS; WHILE MY HAND WAS ON THE BOTTOM OF THE LEVERS. JUST ABOUT 70 KTS I LOOKED TO THE L; SAW A J-31 ON LNDG ROLL COMING AT US ON A XING RWY. I INSTANTLY PULLED THE PWR LEVERS BACK; STEPPED ON THE BRAKES AND THEN HAD TIME TO SAY 'ABORT.' THEN ATC SAID STOP TKOF ROLL. THE CAPT FINISHED SLOWING THE ACFT AS WE EXITED THE RWY. IN MY MIND I FEEL 3 THINGS LED TO THIS: 1) DISCUSSING THE RECENT ACR CRASH BEFORE TKOF. 2) THE FLT ATTENDANT SAYING 'READY FOR TKOF N THE MIDDLE OF OUR CHKLIST. 3) THE FACT THAT I DID THE TKOF PA AT THE LAST MOMENT. I WILL IN THE FUTURE MAKE SURE 1 CHKLIST IS TOTALLY COMPLETE BEFORE STARTING ANOTHER. AND I AM VERY GLAD THAT I CAUGHT 'OUR' MISTAKE BEFORE THERE WAS AN ACCIDENT OR ATC HAD TO SAY STOP. THIS WAS NO DOUBT A LEARNING EXPERIENCE. SUPPLEMENTAL INFO FROM ACN 276247: WE WERE CLRED TO TAXI PAST ATC DELAYED ACFT WAITING FOR TKOF ON RWY 18L. OPS WERE BEING CONDUCTED ON THE INTERSECTING RWY 5 ALSO. WE WERE CLRED INTO POS AND HOLD. FOR SOME UNEXPLAINED REASON; I BEGAN THE TKOF ROLL. THERE WAS AN ACFT LNDG ON RWY 5 WHICH; HAD WE CONTINUED THE TKOF; MAY HAVE BECOME A CONFLICT.