CHAMPAIGN, Ill. - University of Illinois wrestling coach Mark Johnson signed a contract extension to keep him with the Illini through the 2007 season, as announced by Director of Athletics Ron Guenther. Johnson is completing his 12th season at the helm of the Illinois program, one that has seen seven national champions and seven Top-10 NCAA finishes during his tenure.      "Mark has done an exceptional job as wrestling coach and has been a valuable ambassador for our program and the University. I am pleased that he is committed to our program."     "I have always said that Illinois is where I want to finish my career," Johnson said. "I want to continue to lead this team our eventual goal of a national championship and am glad Ron Guenther has made the commitment to me to accomplish that goal."    During his time with the Illini, Johnson has had 12 winning seasons in 12 years and has led the team to nine consecutive Top-12 finishes at nationals. He has taken 95 wrestlers to the NCAA Tournament, with 28 earning All-America honors.     Johnson will take his 2004 edition of eight qualifiers to St. Louis, Mo., to compete for a fifth straight Top-10 placing on March 18-20 at the Savvis Center.