jQuery: how can I select only the checkboxes that are visible and checked?

Question

I\'m trying to check whether or not all the visible check boxes in a certain series are checked and i thought of just counting those that are visible and those that are visible

Answer 1

This is incorrect:

if($j("input[id^='chk_camp']").filter(':visible').filter(':checked).length == $j("input[id^='chk_camp']).filter(':visible').length)
//                                                          ------^------ missing qoutes here      ----^--- also double quotes here