Any one knws hw to upload rtf file in webserver in asp.net.Can any send code of it

it is not any different from normal file upload

Default.aspx :

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
        <asp:FileUpload ID="FileUpload1" runat="server" />
        <asp:Button ID="btnUpload" runat="server" onclick="btnUpload_Click" 
            Text="Upload" />
    
    </div>
    </form>
</body>
</html>

Default.aspx.cs :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btnUpload_Click(object sender, EventArgs e)
    {
        FileUpload1.SaveAs(Server.MapPath("deneme"));
    }
}

you have to set access permissions for ASPNET user too.