asp+ajax无刷新用户注册代码

reg.asp文件

username=request.Form("username")
password=request.Form("password")

sql="select * from puser where y_username='"&username&"'"
rs.open sql,conn,1,1
If Not rs.eof Then
 response.write "no"
 response.end
End If
rs.close

sql="insert into puser(y_username,y_password) values('"&username&"','"&password&"')"
rs.open sql,conn,1,3
response.write "yes"
%>

adoconn.asp文件代码
set rs=server.CreateObject("adodb.recordset")
db="./username.mdb"
Set conn = Server.CreateObject("ADODB.Connection")
connstr="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Server.MapPath(db)
conn.Open connstr
%>

检测用户是否存在

username=Replace(request.querystring("username"),"'","")
sql="select * from puser where y_username='"&username&"'"
rs.open sql,conn,1,1
if rs.eof then
 response.write "no"
else
 response.write "yes"
 end if
 rs.close
 %>

mdb.数据表

y_id 自动编号
y_username text
y_password text

  //创建请求，并使用escape对username编码，以避免乱码
   xmlhttp.onreadystatechange=function()
   {
     if(4==xmlhttp.readyState)
  {
    if(200==xmlhttp.status)
    {
      if (xmlhttp.responseText=="yes")
      {
   this.form1.username.value="";
   this.form1.password.value="";
   this.form1.password1.value="";
   document.getElementById("check1").innerHTML="";
   document.getElementById("password2").innerHTML="";
   document.getElementById("password3").innerHTML="";
   alert('注册成功');
  }
  else
  {
      this.form1.password.value="";
   this.form1.password1.value="";
   alert('注册失败');   
  }
    }
    else
    {
      alert('网络连接失败');
    }
  }
   }
  //打开连接
  xmlhttp.open("post","reg.asp",true)
  xmlhttp.setRequestHeader('Content-type','application/x-www-form-urlencoded');
  //发送数据
  xmlhttp.send("username="+escape(username)+"&password="+escape(password));
 }