The sums and the permutations

The goal of this puzzle is to fill out the empty cells of the grid in such a way that:
- each row contains all digits from 1 to 9;
- each column contains different digits;
- the sum of the digits in each column equals the respective number indicated below the column.
How to play:
- click an empty cell to put a digit in it. The cell will be highlighted.
Now, using the arrow keys you can highlight other empty cells of the grid;
- to move to the next level, click the "Next Level" button;
- to check you solution, click the "Done" button;
- to clear all the digits you have placed already , click the "Reset" button.