结果显示No row count was produced，求。_J2SE

结果显示No row count was produced，求高手指点。。。
<%@ page contentType="text/html; charset=GB2312" %>
<%@ page import="java.sql.*" %>
<html>
<head><title>用户登录</title>
</head>
<body><center>
<% request.setCharacterEncoding("utf-8");
String s_username=request.getParameter("username");
if(s_username==null){
s_username="";
}
String s_password=request.getParameter("password");
if(s_password==null){
s_password="";
}
%>
<font size=4 color=blue>用户登陆</font><hr>
<%
String sql;
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn=DriverManager.getConnection("jdbc:odbc:myselflk","sa","");
Statement stmt=conn.createStatement();
try{
sql="select username from web1.dbo.myself where password='"+s_password+"'";

stmt.executeUpdate(sql);
ResultSet rs; //建立ResultSet(结果集)对象
rs=stmt.executeQuery("select username from web1.dbo.myself where password='"+s_password+"'");
//执行SQL语句
%>
<table border=3>
<tr bgcolor=silver><b>
<td><center>您好！</td><td><center>用户名</td><td><center>登陆成功！</td>
</tr>
<%
//利用while循环将数据表中的记录列出

while (rs.next()){
%>
<tr>
<td width="165"><a class="navText"><center>欢迎光临！</a></td>
<td><font size=2><%= rs.getString("username") %></font></td>
<td width="165"><a href="main.html" class="navText"><center>进入主页>></a></td>
</tr>
<%
}

rs.close(); //关闭ResultSet对象
}
catch(Exception e){
out.println(e.getMessage());
}
stmt.close(); //关闭Statement对象
conn.close(); //关闭Connection对象
%>
</table></center>
<p></p><p></p>
<tr>
<td width="165"><a href="enter.html" class="navText"><center><<重新登录</a></td>
</tr>
</body></html>

------解决方案--------------------

Java code

String sql;                Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");                Connection conn = DriverManager.getConnection("jdbc:odbc:myselflk",                        "sa", "");                Statement stmt = conn.createStatement();                try {                    sql = "select * from web1.dbo.myself where username='"                            + s_username + "'";                    ResultSet rs = stmt.executeQuery(sql);                    if(!rs.next()){                    %>                    <div>用户不存在</div>                                        <%                     }                    rs = stmt                            .executeQuery("select username from web1.dbo.myself where password='"                                    + s_password + "'");                    //执行SQL语句            %>
------解决方案--------------------
你的代码中没有用户名的判断。。。。