Use Tab to move between fields when grading

[novoselt]

At the moment clicking "Enter grade..." open a button "Save" at the top, grade box under it, and a comment area on the bottom. Pressing TAB inside of either box inserts TAB character. I don't see why I would want to enter it there. But I do want to enter the grade, press TAB, enter the comment, press TAB, press Enter to Save:

To do that, TAB should be intercepted and the "Save" button should be at the bottom (it would be strange to move up the form). I am actually not clear why "Save" button is necessary at all.

But what would be logical either after pressing Save or straight after entering the comment for one student, is TAB switching me to Open button of the next student.

No idea how many people would discover and use it, but I was surprised that it didn't work.