谁能告诉我 这句错误是什么意思？出现在那里？在线邓～～！

还是昨天的那段代码 iplinger(罗宾汉)<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<jsp:useBean id="mdb" class="com.db.DatabaseConn" scope="page"/>
<title></title>
</head>
<body>
<%
String sql="";
String sqlstr="";
String sql2="";
sql=(String)session.getAttribute("sql");
ResultSet rs=mdb.Query(sql);
//学生类型
//sqlstr="select * from xueshengleixing";
//ResultSet rsstr=mdb.Query(sqlstr);
//课程类型
//sql2="select * from kechengleixing";
//ResultSet rs2=mdb.Query(sql2);
//System.out.println(rs2.getString(1));
%>
<form action="" method="post">
<table width="1450" border="1" align="center">
<tr>
<td width="80">课程代码</td>
<td width="80">教师代码</td>
<td width="80">课程名称</td>
<td width="80">课程种类</td>
<td width="100">开课日期</td>
<td width="80">学生类型</td>
<td width="90">学生数目</td>
<td width="90">班级数目</td>
<td width="90">授课学时</td>
<td width="90">试验学时</td>
<td width="90">开 新 课</td>
<td width="90">新 开 课</td>
<td>外语授课</td>
<td width="90">有无助教</td>
<td width="90">工 作 量</td>
</tr>
<%
while(rs.next())
{
%>
<tr>
<td><%=rs.getString(1)%></td>
<td><%=rs.getString(2)%></td>
<td><%=rs.getString(3)%></td>
<td>
<select>  
<%//课程种类
sql2="select * from kechengleixing";
ResultSet rs2=mdb.Query(sql2);
  while(rs2.next())
  {
%>
<option value="<%=rs2.getString(1)%>" 
<%
if((rs2.getString(1)!=null && rs2.getString(1).equals(rs.getString(4)))){out.print("selected");}
//System.out.println(rs2.getString(1));
//System.out.println(rs.getString(4));
%>
><%=rs2.getString(1)%></option>
<%   
   }
%>
</select>
</td>
<td><%=rs.getString(5)%></td>
<td>
<select>
<%//学生类型
sqlstr="select * from xueshengleixing";
ResultSet rsstr=mdb.Query(sqlstr);
while(rsstr.next())
{
%>
<option value="<%rsstr.getString(1)%>" 
<%
if((rsstr.getString(1)!=null && rsstr.getString(1).equals(rs.getString(6)))){out.print("selected");}
System.out.println(rsstr.getString(1));
System.out.println(rs.getString(6));
%>
><%=rsstr.getString(1)%></option>
<%
}
%>
</select>
</td>
<td><%=rs.getString(7)%></td>
<td>
<select>
<%//班级数目
 for(int i=1;i<=8;i++)
 {
%>
<option value="<%=i%>"<%if(i==rs.getInt(8))out.print("selected");%>><%=i%></option>
<%
 }
%>
</select>
</td>
<td><%=rs.getString(9)%></td>
<td><%=rs.getString(10)%></td>
<td>
<select>
<option value="1" <%if(rs.getInt(11)==1)out.print("selected");%>>是</option>
<option value="0" <%if(rs.getInt(11)==0)out.print("selected");%>>否</option>
</select>
</td>
<td>
<select>
<option value="1" <%if(rs.getInt(12)==1)out.print("selected");%>>是</option>
<option value="0" <%if(rs.getInt(12)==0)out.print("selected");%>>否</option>
</select>
</td>
<td>
<select>
<option value="1" <%if(rs.getInt(13)==1)out.print("selected");%>>是</option>
<option value="0" <%if(rs.getInt(13)==0)out.print("selected");%>>否</option>
</select>
</td>
<td width="57">
<select>
<option value="1" <%if(rs.getInt(14)==1)out.print("selected");%>>是</option>
<option value="0" <%if(rs.getInt(14)==0)out.print("selected");%>>否</option>
</select>
</td>
<td><%=rs.getLong(15)%></td>
</tr>
<%
}
%>
</table>
</form>
</body>
</html>