My search currently searches through all the table fields - I would like it to only search the ones that have a td class of test.

Im using
$('input#SearchBox').quicksearch('table#tablesorter-demo tbody tr');
This searches all the fields in the table, I have tried:

$('input#SearchBox').quicksearch('table#tablesorter-demo tbody tr td.test');
but this just stops the whole search from working.

I also tried:
'$('input#SearchBox').quicksearch('table#tablesorter-demo tbody tr', {'selector': 'td.test'});
But this doesnt find anything...

Ideas appreciated?