请教错误

我有一下代码通过他连接mysql数据库的 可是他都直接报错"用户名 秘密错误的"我找不到错误呀 
<%@page contentType="text/html;charset=GBK"%>
<%@page import="java.util.*"%>
<%@ page import="java.sql.*" %>
<jsp:useBean id="sqlbean" scope="page" class="database.sqlbean">
</jsp:useBean>
<html>
<head>
<title>登录检查</title>
</head>
<body><%String userType = request.getParameter("userType");
String regName=sqlbean.AsciiToChineseString(request.getParameter("username").trim());
String regPassword=request.getParameter("password");
regPassword=regPassword.trim();
session.setAttribute("originname",regName); if (userType.equals("Y"))
 {
   ResultSet rs=null;
   String sqlstring = "select * from chatuser where USERNAME='"+ regName +"' and PASSWORD='"+ regPassword + "'";;
   rs = sqlbean.executeQuery(sqlstring);
   if(rs.next())
   {     String experience=rs.getString("experience");
     String userlevel=rs.getString("userlevel");
     session.setAttribute("experience",experience);
     session.setAttribute("userlevel",userlevel);       regName = regName + "[会员]";     session.setAttribute("username",regName);     rs.close();
     sqlbean.freeRs(rs);
     response.sendRedirect ("chat.jsp");
   }
   else
   {
     rs.close();
     out.print("<script>alert(\"用户名/密码错误!\");");
     out.print("window.location = \"login.jsp\"</script>");
   }
 }
 else
 {
if((regName.length()<1)||(regName.length()>10)) {
out.print("<script>alert(\"游客名不能超过6个字长!\");window.close();</script>");
return;
} Character c=new Character(' ');
for(int i=0;i<regName.length();i++) {
if(regName.charAt(i) == c.charValue()) {
out.print("<script>alert(\"名字中间不能有空格!\");window.close();</script>");
return;
}
}
       regName = regName + "[非会员]";
 }