How to upload file in ASP.NET

Introduction :
This code will help you understand how to use file upload control in asp.net and the code to upload the file on specific folder path.

Code:

       string iim = DateTime.Now.ToString("ddMMyyyyHHmmss"); //prefis of file name to upload
                if (FileUpload01.HasFile)
                {
                    string f1 = Path.GetFileName(FileUpload01.PostedFile.FileName);
                    string[] xx = f1.Split('.');  // to get posted file extension
                    string a = iim + "_" + xx[1].ToString();
                    FileUpload01.SaveAs(Server.MapPath("~/FolderPath/") + a);
                }