[рони]

lolka84,
посмотрите тут
и возможный вариант

function summitog1() {
  var table = document.getElementById("one"),
  summyeval = document.getElementById("summitogye1"),
  summrurval = document.getElementById("summitogrur1"),
  sumye=0,sumrur=0;
    for (var i=1;i<table.rows.length-2;i++) {
      var td = table.rows[i],o1 = td.cells[4],o2 = td.cells[5];
          o1 = o1.getElementsByTagName('input')[0];
		  o2 = o2.getElementsByTagName('input')[0];
      if(!isNaN(Number(o1.value)))sumye +=Number(o1.value);
      if(!isNaN(Number(o2.value)))sumrur +=Number(o2.value);
      	}
	if (sumye && sumrur ){
      summyeval.value = (sumye).toFixed(2);
      summrurval.value = (sumrur).toFixed(2);
	}
}