Is there an on_tab_on2 event

I have a thumb gallery where I can hover over each thumb to trigger an associated pop-up to appear, but I would like to be able to also tab through the thumbs
and make the associated pop-ups appear... Any help on how to go about doing this?

function onhovering_and_tabbingon2()
{
$(".box img").hover(
function ()
{
var num = $(this).attr('id').replace('thumb_entry_No', '');

$('#pop' + num).toggleClass('popup');

// maybe set the tabbing position to here... ???
},

function ()
{

var num = $(this).attr('id').replace('thumb_entry_No', '');

$('#pop' + num).toggleClass('popup');

}
);


// todo: try to show the popups when tabbing through the thumbs...
$(".box img").on_tab_on2( // on_tab_on2 ????
function () {

var num = $(this).attr('id').replace('thumb_entry_No', '');

$('#pop' + num).toggleClass('popup');

// alert("Thumb entry no. " + num + " was tabbed to...");


// might also have to move the mouse pointer(if there is one) along also.... ???
},

function () {

var num = $(this).attr('id').replace('thumb_entry_No', '');

$('#pop' + num).toggleClass('popup');

}
);

}