The Cowboys began their 2007 campaign at home against their NFC East rival, the New York Giants.  In the first quarter, Dallas trailed early as QB Eli Manning completed a 60-yard TD pass to WR Plaxico Burress to give New York an early 6-0 lead (botched hold on PAT).  Afterwards, the Cowboys got on the board with rookie kicker Nick Folk getting a 31-yard field goal.  In the second quarter, Dallas took the lead with RB Marion Barber getting an 18-yard TD run, while QB Tony Romo completed an 18-yard TD pass to TE Jason Witten.  Afterwards, the Giants would end up trailing by one at halftime, as Manning & Burress hooked up with each other again on a 4-yard TD pass, while kicker Lawrence Tynes got a 44-yard field goal. In the third quarter, Dallas responded with Romo completing a 22-yard TD pass to WR Terrell Owens.  New York would climb back with Tynes kicking a 48-yard field goal, but the Cowboys answered with Romo running into the end zone from 9 yards out.  In the fourth quarter, the Giants managed to try to come back with Tynes' 24-yard field goal, yet Dallas would reply with Romo & Owens hooking up with each other again on a 47-yard TD pass.  Just when it looked like New York was drawing closer with Manning's 9-yard TD pass to RB Derrick Ward (with a failed 2-point conversion) and his 10-yard TD pass to Burress, the Cowboys sealed the win with Romo completing a 51-yard TD pass to WR Sam Hurd.
Question: How many TD's did Tony Romo score after the second quarter?
Answer: 4