Image Update Problem in asp.net

HI ALL
  I am uploading and updating images in m application and storing the images in Folder in my application's root directory. But, on click of Update button i have followinf code first i delete the file from the folder and then Save another file with same imageid.

File.Delete(Server.MapPath("ECG\\") + ecgid + "." + ext[1]);
                 
fluploadecg.PostedFile.SaveAs(Server.MapPath("ECG\\") + ecgid + "." + ext[1]);// System.IO.Path.GetFileName(hpf.FileName));
                       
                        imgcardio.Visible = true;
        ...