if you push "Enter" or "Shift + Enter", you can move your focus vertically.
please read jquery.verticallytablefocus.js .
<head>
<script type="text/javascript" src="./jquery.verticallytablefocus.js"></script>
</head>and then apply verticallytablefocus function.
// apply vertical table focus.
$("#target_table").applyVerticalTableFocus();