Version History - SUDOKU Puzzle [ 2007] 1.0 - Initial Version [Aug. 2008] 1.1 - minor bug fix [Jul. 2009] 1.2 - Different Logo Images for Different Types of SUDOKU are added. [Jan. 2010] 1.3 - minor bug fix [Apr. 2010] 1.5 - Undo and Redo feature added [Jan. 2011] 2.0 - minor bug fix - auto logging feature added - auto coloring feature added - hybrid mode added