How to upload a file and how to download from folder.

Design page

<asp:FileUpload ID="flUpload" runat="server" />

Code behind

protected void submit_Click(object sender, ImageClickEventArgs e)
    {
        string ID=textbox1.text;
        flUpload.SaveAs(Server.MapPath("user_doc/" + ID + ".doc"));
    }

Assuming this is ASP, then place a FileUpload control on your page, and handle the OnClick event:

string filename = Path.GetFileName(MyFileUpload.FileName);
MyFileUpload.SaveAs(Mypath + filename);

To download it, just add a link to the file top your web page - the client browser will do the rest.

Check these links
http://blogs.msdn.com/b/stcheng/archive/2009/03/20/asp-net-how-to-implement-file-upload-and-download-in-asp-net-mvc.aspx[^]

File Upload with ASP.NET[^]

http://www.mikesdotnetting.com/Article/125/ASP.NET-MVC-Uploading-and-Downloading-Files[^]