为什么出现此现象？

在注册页面点击确定执行以下jsp文件
<%@ page contentType="html/text; charset=gb2312" %>
<%@ page import="java.util.*" %>
<jsp:useBean id="sqlbean" scope="session" class="com.seagull.dbconnect.SQLConnect" /><%
String strname=sqlbean.to_8859_1(request.getParameter("name"));
String username=sqlbean.to_8859_1(request.getParameter("username"));
String password=sqlbean.to_8859_1(request.getParameter("password"));
String question=sqlbean.to_8859_1(request.getParameter("question"));
String answer=sqlbean.to_8859_1(request.getParameter("answer"));
String depart=sqlbean.to_8859_1(request.getParameter("company"));
String mobile=sqlbean.to_8859_1(request.getParameter("mobile"));
String telnum=sqlbean.to_8859_1(request.getParameter("telnum"));
String email=sqlbean.to_8859_1(request.getParameter("email"));
String pagesize=sqlbean.to_8859_1(request.getParameter("pagesize"));
String remoteIP= request.getRemoteAddr();

Calendar now=Calendar.getInstance();
String sj=now.get(Calendar.YEAR)+"-"+now.get(Calendar.MONTH)+1+"-"+now.get(Calendar.DAY_OF_MONTH)+" "+now.get(Calendar.HOUR_OF_DAY)+":"+now.get(Calendar.MINUTE)+":"+now.get(Calendar.SECOND);
String sql="select * from RegUser where username='"+strname+"' or rname='"+username+"'";
sqlbean.executeQuery(sql);

if(sqlbean.next())
{
                      out.println("用户名重复！请重试");
}
else
{
sql="insert into RegUser(rname, username, password, depart, email, question, answer, regtime, IP, phone, mobile, pagesize) values ('"
+ username + "','" + strname + "','" + password + "','" + depart + "','" + email + "','" + question + "','" + answer + "','"+ sj + "','"
+ remoteIP + "','" + telnum + "','" + mobile + "'," + pagesize + ")" ;

sqlbean.executeUpdate(sql);
System.out.println(sql);

sql="select ID from RegUser where username='"+ strname+"'" ;
sqlbean.executeQuery(sql);
if(sqlbean.next())
{
sql="insert into userinfo(userid, username, Ltime, phone, mobile, email) values ('"
+ sqlbean.getString("ID") + "','" + username + "','" + sj + "','" + telnum + "','" + mobile + "','" + email + "')";
sqlbean.executeUpdate(sql);
out.println("用户注册成功！");
}
}
sqlbean.close();
%>
用户注册信息都写进数据库了，可是不显示用户注册成功信息，最奇怪的是弹出下载文件对话框，请各位赐教！谢谢