Simple Sudoku Helper

1   +   +     +   4   +     +   +   2   +   5   +     +   +   +     +   9   +   +   +   8     +   +   +     3   +   +     +   +   +     5   +   9     +   +   +   7   +   +     +   8   +     +   +   3   +   +   +     7   +   6     +   +   +     +   +   7     +   +   +     5   +   +   +   9   +     +   +   +     +   4   +   6   +   +     +   2   +     +   +   1

Enter some numbers and press "Update" Cells that contain just a number are completed; the only option provided by the drop-down box is bk (for "back") which will un-set the box. Cells that contain a number in square brackets are currently uncompleted; the number shows how many legal entries there are, and the drop-down box permits the selection of one of those legal entries. Get Another One

bk1 [3]367 [3]369 [4]3689 bk4 [4]3578 [3]678 [4]5678 bk2 [3]234 bk5 [4]2346 [5]12368 [4]1367 [5]12378 [5]14678 bk9 [4]4678 [3]249 [4]2467 bk8 [4]1269 [5]15679 [4]1257 bk3 [4]1567 [4]4567 [4]2348 [6]123468 [5]12346 bk5 [2]13 bk9 [6]124678 [5]12678 [4]4678 bk7 [4]1246 [6]124569 [3]124 bk8 [3]124 [5]12469 [4]1256 bk3 [6]234589 [5]12348 [6]123459 bk7 [2]13 bk6 [5]12489 [4]1258 [4]4589 [4]2348 [5]12348 bk7 [6]134689 [4]1369 [4]1348 bk5 [4]2368 [3]689 [4]2358 bk9 [4]1235 [4]1368 [5]13567 [5]13578 [4]2678 bk4 [3]678 bk6 [3]348 [3]345 [4]3489 bk2 [5]34578 [3]789 [3]378 bk1