Below is what you need for a “select all” checkbox to toggle the rest of the checkboxes. Below assumes your checkboxes all have the name “my_chkboxes[]”.
$('#my_select_all').click(function(){
$("input[name='my_chkboxes[]']").each(function (index, el) {
if ($('#my_select_all').is(':checked')) {
$(el).attr('checked', 'checked');
}else{
$(el).attr('checked', false);
}
});
});