jQuery search in fields with a specific td class

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.

I'm 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 whol开发者_开发知识库e search from working.

I also tried:

'$('input#SearchBox').quicksearch('table#tablesorter-demo tbody tr', {'selector': 'td.test'})'

But this doesn't find anything.

I think this should help

$('#SearchBox').quicksearch('#tablesorter-demo tbody tr td .test');