>>Thanks for trying - but - like Mark said, each 3x3 grid has to have the numbers 1-9 as well. Also, it needs to be in some random order - making it more difficult to solve.
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>I just started solving Sudoku puzzles recently.
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>The real difficulty for programming, it seems to me, is not so much how to put the digits in some random order and still make them fit - although I have not the slightest idea to solve it that part. The real difficulty might be to decide which digits to leave blank, so that a human can then solve the puzzle.

I've come to this conclusion...but haven't got it programmed yet...you need to fill in a few (maybe 9 spaces) with numbers from 1 to 9 - then attempt to solve the puzzle programmatically. If you can find a solution, then it's simply a matter of removing all but about 15 or so of the numbers and let the user try to solve it. It is really a very difficult thing to program. I'm finding that there are many programs that have pre-programmed puzzles and just load a puzzle instead of generating a new one.

Let me know if you come up with something - I'd be very interested in taking a look.