I checked "select_all", which successfully checked all checkboxes with class "checkbox_read". I then unchecked "select_all" which successfully UNchecked all checkboxes with class "checkbox_read."

Then I checked "select_all", again which failed to check all checkboxes with class "checkbox_read."

I found this bug after upgrading my JQuery library from 1.7.1 to 1.9.1. when I downgraded, the error did not manifest itself.

Code is below:

$('#select_all').click(function()

{

if(this.checked)

{

$('.checkbox_read').attr('checked', 'checked');

}

else

{

$('.checkbox_read').attr('checked', false);

}

});