VS2005上传一个以当时的时间为名字的程序

新建一个FileUpload，再打入如下代码：
public partial class project3_project3_project3_upload : System.Web.UI.Page
{

protected void Button1_Click(object sender, EventArgs e)
{
string upfile = @"d:\0";
if (FileUpload1.HasFile)
{
string filename = FileUpload1.PostedFile.FileName;
int i =FileUpload1.PostedFile.FileName.LastIndexOf(".");
string b = FileUpload1.PostedFile.FileName.Substring(i);
Random ran = new Random();
int a = ran.Next(100, 1000);
string mon, day, hour, min;
mon = DateTime.Now.Month.ToString();
if (mon.Length == 1)
mon = "0" + mon;
day = DateTime.Now.Day.ToString();
if (day.Length == 1)
day = "0" + day;
hour = DateTime.Now.Hour.ToString();