How many times did Tom Landry take the Dallas Cowboys to the Super Bowl?

There have been seven Dallas Cowboys head coaches since Tom Landry's departure after the 1988 season. The coaches were: Jimmy Johnson (1989-1993), Barry Switzer (1994-1997), Chan Gailey (1998-1999), Dave Campo (2000-2002), Bill Parcells (2003-2006), Wade Phillips (2007-2010) and Jason Garrett (2010-present).