用C#写上传程序要怎么写！！

<HTML>
<HEAD>
<title>上传多个文件</title>
<Script Language="c#" Runat="Server">
public void DoUpload (Object src,EventArgs e)
{
int FileCount=Request.Files.Count;
String Uploadfilename;
String[] AFilename;
char[] de={'\\'};
for (int i=0;i<FileCount ;i++ )
{
HttpPostedFile hpf=Request.Files[i];
if(hpf.FileName!="")
{
AFilename=hpf.FileName.Split(de);
Uploadfilename=AFilename[AFilename.Length-1];
hpf.SaveAs(Server.MapPath(".")+"\\"+Uploadfilename);
AddPanelControls(Uploadfilename);
}
    
}
}
public void AddPanelControls(String filename)
{
Label lblShow=new Label();
lblShow.Text=filename+"已经上传的文件<br/>";
Panel1.Controls.Add(lblShow);
}
</Script>
</HEAD>
<body>
<b>上传多个文件</b>
<hr>
<form Enctype="multipart/form-data" runat="Server" ID="Form1">
文件1:<input type="file" size="30" id="UploadFile1" runat="Server" NAME="UploadFile1">
<br>
文件2:<input type="file" size="30" id="UploadFile2" runat="server" NAME="UploadFile2">
<br>
文件3:<input type="file" size="30" id="UploadFile3" runat="server" NAME="UploadFile3">
<br>
文件4:<input type="file" size="30" id="UploadFile4" runat="server" NAME="UploadFile4">
<br>
文件5:<input type="file" size="30" id="UploadFile5" runat="server" NAME="UploadFile5">
<br>
<input type="submit" value="上传" onServerClick="DoUpload" runat="server" ID="Submit1" NAME="Submit1">
<br>
</form>
<hr>
<asp:Panel id="Panel1" runat="server" />
</body>
</HTML>