JQuery :: Possible To Select Element With Focus

Is it possible to extend jquery to include a function that will select elements with focus. In the same way :input selects all inputs :selected selects all selected etc but instead :focus or focused: which would select the focused element. I have a table which includes an input field on each row (like a simple datagrid). Id like to be able to hit an access key and delete the row (input textbox) which has focus ie the row which the cursor has been placed in.

I found this but it selects the first input textbox only for some reason?... and not the one with focus.
$.extend($.expr[':'], {
focused: function(elem) { return elem.hasFocus; }
});
var id = $('input :focused').val();
console.log(id);