How to find table tr td using Jquery

  $('table tr').each(function () {
                //if ($(this).find('.ruletype').eq(0).text() == $("#RuleType").val()) {
                //    alert('Already taken');
                //}
                if ($(this).find('.threshhold').eq(0).text() == $("#txtThresholdDays").val()) {
                    alert('Already taken');
                }
            });

#Ruletype is id and .ruletype is class