image in current folder not deleted upon new upload
protected void UploadButton_Click(object sender, EventArgs e)
 {
   if (FileUploadControl.HasFile)
   {
      try
      {
        string theUserId = Session["UserID"].ToString();
        OdbcConnection cn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver}; Server=localhost; Database=gymwebsite2; User=x; Password=x;");
        cn.Open();

        OdbcCommand sc = new OdbcCommand(string.Format("SELECT picturepath FROM Pictures WHERE UserID ='{0}'", theUserId), cn);
        OdbcDataReader reader = sc.ExecuteReader();

        while (reader.Read())
        {
          if (System.IO.File.Exists(Convert.ToString(reader[0])))
          {
            System.IO.File.Delete(Convert.ToString(reader[0]));
          }
        }

        string filenameDB = Path.GetFileName(FileUploadControl.FileName);
        string fileuploadpath = Server.MapPath("~/userdata/" + theUserId +
                                "/uploadedimage/") +
                                Path.GetFileName(FileUploadControl.FileName);
        FileUploadControl.SaveAs(fileuploadpath);
        string fileuploadpaths = ("~/userdata/" + theUserId + "/uploadedimage/") +
                                 filenameDB;
        StatusLabel.Text = "Upload status: File uploaded!";

        OdbcCommand cmd = new OdbcCommand("INSERT INTO Pictures (UserID, picturepath) VALUES ('" + theUserId + "','" + fileuploadpaths + "')", cn);
        cmd.ExecuteNonQuery();
      }
      catch (Exception ex)
      {
        StatusLabel.Text = "Upload status: The file could not be uploaded. The following error occured: " + ex.Message;
      }
    }
  }
}

OdbcCommand sc = new OdbcCommand(string.Format("SELECT picturepath FROM Pictures WHERE UserID ='{0}'", theUserId), cn);
OdbcDataReader reader = sc.ExecuteReader();

while (reader.Read())
{
  if (System.IO.File.Exists(Convert.ToString(reader[0])))
  {
    System.IO.File.Delete(Convert.ToString(reader[0]));
  }
}

string filenameDB = Path.GetFileName(FileUploadControl.FileName);
string fileuploadpath = Server.MapPath("~/userdata/" + theUserId +
                        "/uploadedimage/") +
                        Path.GetFileName(FileUploadControl.FileName);
FileUploadControl.SaveAs(fileuploadpath);
string fileuploadpaths = ("~/userdata/" + theUserId + "/uploadedimage/") +
                         filenameDB;
StatusLabel.Text = "Upload status: File uploaded!";

OdbcCommand cmd = new OdbcCommand("INSERT INTO Pictures (UserID, picturepath) VALUES ('" + theUserId + "','" + fileuploadpaths + "')", cn);
cmd.ExecuteNonQuery();

// Even though you've just calculated the result of Path.GetFileName you
// redo it here?
string fileuploadpath = Server.MapPath("~/userdata/" + theUserId
                        + "/uploadedimage/")
                        + Path.GetFileName(FileUploadControl.FileName);
FileUploadControl.SaveAs(fileuploadpath);

string filenameDB = Path.GetFileName(FileUploadControl.FileName);
string fileuploadpaths = ("~/userdata/" + theUserId + "/uploadedimage/") +
                         filenameDB;

System.IO.File.Delete(Convert.ToString(reader[0]));

System.IO.File.Delete(Server.MapPath(Convert.ToString(reader[0])));