Change focus in a input grid form

[alphabit]

I wonder how I can change the focus to the next element(input field in a form) using java script. I believe that it is posible to write a function that can be event triggered in (onkeyup event, maybe ...) when the limit (maxlength="1" in my case) is reached. I'm a "null programer" in java script, so I try to find some help.
I intend to use a java script trick in a input grid (crossword solver), in order to avoid entering the solution letter by letter in the grid.
I'm wonder if it is posible to use somehow the arrows keys to move across the grid.
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the field names are generated automatically by php and looks like:
name="lit_1_2" where 1 is the row and 2 is the col.
A cell looks like:

:sad:

[tgreer]

Hello. Please use the forum's code and formatting tags, and avoid things like "######" in your posts.

What have you already tried? Are you familiar with JavaScript's events and event handlers? You might investigate using the "onkeypress" or related event handlers. The particular keycode being generated will be a property of the Event object.

You can set focus to any particular element by using the "focus()" method.

So: research "JavaScript", onkeypress", "focus" and "Event". Web Searches might be "JavaScript Event object" and "JavaScript onkeypress", etc. Apply what you discover, try it, and come back with any specific questions.