我不知道问题出现在什么地方？请大家帮帮我

<%@ page contentType= "text/html; charset=GBK" import="java.sql.*"%>
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=gb2312"> 
<title>产品发运通知单</title> 
</head> 
<body>
   
  <%   //取提交按钮传出的数据
      String strSub=request.getParameter("submit");
      //若未取得则建立表单使用者输入数据
      //若有取得数据，则将数据新增至数据库中
      if(strSub==null)
    {
    session.setAttribute("Done","");//重设变量值
  %>
<form name="form1" method="post" action="chanpinfayun.jsp">
<table border="1" align=center bgcolor="#ccccff"> 
<caption align=top><h3>赣 州 华 兴 钨 制 品 有 限 公 司</h3>
<br><h1><u>产品发运通知单</u></h1>
<br><div align="right">第<input name="k_number" type="text" size="8">号</div></tr></caption>
<tr>
<th rowspan=2 nowrap>品&nbsp;&nbsp;号</th>
<th colspan=4>计&nbsp;划&nbsp;量</th>
<th rowspan=2>收&nbsp;货&nbsp;单&nbsp;位</th>
<th rowspan=2>到&nbsp;&nbsp;站</th>
<th rowspan=2>供货期</th>
</tr>
<tr>
<th>批号</th>
<th>规格</th>
<th>数量</th>
<th>件数</th>
</tr>
<tr>                   
<td><div align="center"> 
        <input name="sample_name" type="text" size="10">
      </div></td>
    <td><div align="center"> 
        <input name="plan_batchNUM" type="text" size="5">
      </div></td>
    <td><div align="center">
        <input name="plan_Specification" type="text" size="5">
      </div></td>
    <td><div align="center">
        <input name="plan_quantity" type="text" size="5">
      </div></td>
    <td><div align="center">
        <input name="plan_number" type="text" size="5">
      </div></td>
    <td><div align="center">
        <input name="goods_unit" type="text" size="15">
      </div></td>
    <td><div align="center">
        <input name="arrive_station" type="text" size="10">
      </div></td>
    <td><div align="center">
        <input name="Provide_time" type="text" size="10">
      </div></td>
</tr>
<tr>
<th><br>备<br><br><br>注<br><br></th>
<td colspan=10><table width="100%" height="100%" border=0 cellpadding="0" cellspacing="0">
               <tr><td><div align="left">
               <TEXTAREA name="ras" rows=8 cols=68 wrap=soft></TEXTAREA></div></td>
               </tr>
               </table>
</td>
</tr>
<tr>
<th>签发人:</th>
<td colspan=10><table width="100%" height="100%" border=0 cellpadding="0" cellspacing="0">
        <tr><td>
        <input name="sign_person" type="text" size=8></td>
        <td align="center">领单人:<input name="get_person" type="text" size=8></td>
        <td align="right"><input name="year_time" type="text" size=5>年<input name="month_time" type="text" size=2>月<input name="date_time" type="text" size=2>日</td>
        </tr></table>
</td>
</tr></table>
<center><p>
<div align="right"><input type="submit" value="保存" name=submit>&nbsp;&nbsp;&nbsp;&nbsp;</div>
</p></center>
</form>
<%
}else{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver"); 
String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=aaa"; 
String user="sa"; 
String password="123"; 
Connection conn= DriverManager.getConnection(url,user,password); 
Statement stmt=conn.createStatement(); if(session.getAttribute("Done")!="yes") 
{//判断Done变量的值，避免使用者按下“刷新”按钮重复动作
String k_number1=request.getParameter("k_number");
String k_number=new String(k_number1.getBytes("ISO-8859-1"),"gbk");String sample_name0=request.getParameter("sample_name");
String sample_name=new String(sample_name0.getBytes("ISO-8859-1"),"gbk");String plan_batchNUM0=request.getParameter("plan_bathcNUM");
String plan_batchNUM=new String(plan_batchNUM0.getBytes("ISO-8859-1"),"gbk");String plan_Specification0=request.getParameter("plan_Specification");
String plan_Specification=new String(plan_Specification0.getBytes("ISO-8859-1"),"gbk");String plan_quantity0=request.getParameter("plan_quantity");
String plan_quantity=new String(plan_quantity0.getBytes("ISO-8859-1"),"gbk");String plan_number0=request.getParameter("plan_number");
String plan_number=new String(plan_number0.getBytes("ISO-8859-1"),"gbk");String goods_unit0=request.getParameter("goods_unit");
String goods_unit=new String(goods_unit0.getBytes("ISO-8859-1"),"gbk");String arrive_station0=request.getParameter("arrive_station");
String arrive_station=new String(arrive_station0.getBytes("ISO-8859-1"),"gbk");String Provide_time0=request.getParameter("Provide_time");
String Provide_time=new String(Provide_time0.getBytes("ISO-8859-1"),"gbk");
String sample_name04=request.getParameter("sample_name3");
String sample_name3=new String(sample_name04.getBytes("ISO-8859-1"),"gbk");String plan_batchNUM04=request.getParameter("plan_bathcNUM3");
String plan_batchNUM3=new String(plan_batchNUM04.getBytes("ISO-8859-1"),"gbk");String plan_Specification04=request.getParameter("plan_Specification3");
String plan_Specification3=new String(plan_Specification04.getBytes("ISO-8859-1"),"gbk");String plan_quantity04=request.getParameter("plan_quantity3");
String plan_quantity3=new String(plan_quantity04.getBytes("ISO-8859-1"),"gbk");String plan_number04=request.getParameter("plan_number3");
String plan_number3=new String(plan_number04.getBytes("ISO-8859-1"),"gbk");String goods_unit04=request.getParameter("goods_unit3");
String goods_unit3=new String(goods_unit04.getBytes("ISO-8859-1"),"gbk");String arrive_station04=request.getParameter("arrive_station3");
String arrive_station3=new String(arrive_station04.getBytes("ISO-8859-1"),"gbk");String Provide_time04=request.getParameter("Provide_time3");
String Provide_time3=new String(Provide_time04.getBytes("ISO-8859-1"),"gbk");
String res1=request.getParameter("res");
String res=new String(res1.getBytes("ISO-8859-1"),"gbk");String sign_person1=request.getParameter("sign_person");
String sign_person=new String(sign_person1.getBytes("ISO-8859-1"),"gbk");
String get_person1=request.getParameter("get_person");
String get_person=new String(get_person1.getBytes("ISO-8859-1"),"gbk");
String year_time1=request.getParameter("year_time");
String year_time=new String(year_time1.getBytes("ISO-8859-1"),"gbk");String month_time1=request.getParameter("month_time");
String month_time=new String(month_time1.getBytes("ISO-8859-1"),"gbk");String date_time1=request.getParameter("date_time");
String date_time=new String(date_time1.getBytes("ISO-8859-1"),"gbk");String strSQL="INSERT INTO carry_product(k_number,sample_name,plan_batchNUM,plan_Specification,plan_quantity,plan_number,goods_unit,arrive_station,Provide_time,res,sign_person,get_person,year_time,month_time,date_time)Values('"+k_number+"','"+sample_name+"','"+plan_batchNUM+"','"+plan_Specification+"','"+plan_quantity+"','"+
plan_number+"','"+goods_unit+"','"+arrive_station+"','"+Provide_time+"','"+res+"','"+sign_person+"','"+get_person+"','"+year_time+"','"+month_time+"','"+date_time+"')";stmt.executeUpdate(strSQL);
}
session.setAttribute("Done","yes");
//将session对象中的Done设为yes时，避免使用者按下“刷新”按钮重复动作
%>
<p>已将数据将新增至数据库中</p>
<%
ResultSet rs=stmt.executeQuery("select * from carry_product");
%>
<table width=85% border=1>
 <tr>
    <td>编号</td>
    <td>品名</td>
    <td>批号</td>
    <td>规格</td>
    <td>数量</td>
    <td>件数</td>
</tr>
<%
  while(rs.next())
   {
  %>
  <tr>
<td><%=rs.getString("k_number")%></td>
<td><%=rs.getString("sample_name")%></td>
<td><%=rs.getString("plan_batchNUM")%></td>
<td><%=rs.getString("plan_Specification")%></td>
<td><%=rs.getString("plan_number")%></td>
<td><%=rs.getString("plan_quantity")%></td>
</tr>
<%
}
%>
</table>
<%
rs.close();
stmt.close();
conn.close();
%>
<hr>
<a href="chanpinfayun.jsp">新增数据</a>
<%
}
%>
</body>
</html>