javascript 操作表格实现批发功能

<script type="text/javascript">  function calc()  {  //var unitprice = document.getElementById("prices").value;  var stocks = document.getElementById("stock").value;  if(isNaN(stocks))  {  document.getElementById("stock").value = "";  alert("Quantity entered must be a number!");  }  else  {    lots = document.getElementById("lot").value;  if(parseInt(stocks)>parseInt(lots))  {  document.getElementById("stock").value = lots;  stocks = lots;  }  document.getElementById("nums").innerHTML = stocks;  }  var whelestab = document.getElementById("wholeslist");  var maxlot = getprice(whelestab.rows[whelestab.rows.length-1].cells[0].innerHTML);  if(parseInt(maxlot[1]) < parseInt(stocks))  {  stocks = maxlot[1];  document.getElementById("nums").innerHTML = maxlot[1];  document.getElementById("stock").value = maxlot[1];  }  for(i=1;i<whelestab.rows.length;i++)  {  var quan = getprice(whelestab.rows[i].cells[0].innerHTML);  if(parseInt(quan[0]) <= parseInt(stocks) && parseInt(stocks) <= parseInt(quan[1]))  {  //alert(whelestab.rows[i].cells[1].innerHTML);  document.getElementById("unitpric").innerHTML = whelestab.rows[i].cells[1].innerHTML;  document.getElementById("prices").value = parseFloat(document.getElementById("unitpric").innerHTML.replace("USD ",""));  break;  }  }  document.getElementById("total").innerHTML = ((parseFloat(document.getElementById("unitpric").innerHTML.replace("USD ","")) * stocks)-parseFloat(document.getElementById("shipping").value)).toFixed(2);  document.getElementById("productpric").innerHTML = (parseFloat(document.getElementById("unitpric").innerHTML.replace("USD ","")) * stocks).toFixed(2);  }    function getprice(prices)  {  var prices = prices.replace(" --- "," ");  var pric = prices.split(" ");  return pric;  }    </script>