Question

I am having a problem with my jQuery code in that for some reason it doesn’t distinguish between checked and unchecked checkboxes in my situation. It recognises them on the first account (i.e. if it is unchecked to begin with, it recognises that it is in fact unchecked). But if you then uncheck it, it still thinks that it is unchecked.

You can see here:
http://jsfiddle.net/3BZp4/1/

When checked, it will copy the row to the second table, but when you uncheck that same row, it still copies to the second table despite the selector asking for only unchecked rows.

$('#one tbody tr td input.checkbox:not(:checked)').on('change', function (e)
{ });

Answer 1

You can try something like this:

$(':checkbox').on('change', function() {
  if(this.checked) {
     // do if checked
  } else {
    // do if not checked
  }
});

Your complete code will:

$('#one tbody tr td input.checkbox').on('change', function(e) {
    if (this.checked) {
        var row = $(this).closest('tr').html();
        $('#two tbody').append('<tr>' + row + '</tr>');
    }
});

Check this DEMO