The Cowboys have signed veteran Brad Johnson to a three year contract to back up Tony Romo.  He played in 15 games (14 starts) last season for the Minnesota Vikings and he completed 270 of 439 passes (61.5%) for 2,750 yards with 9 TD passes and 15 interceptions (72.0 QB Rating).  He also carried the football 29 times for 82 yards (2.8 ypc) with 1 TD run.  This was a good signing for the Cowboys as insurance in case Romo was a fluke.