Adding file attachment in custom list programmatically

Code:

SPSecurity.RunWithElevatedPrivileges(delegate()

                {

                    SPSite mySite = new SPSite(“Site Url”); //Mentioned site url

                   SPWeb spweb = mySite.OpenWeb();

                    SPList list = spweb.Lists[“HR Policies”];

                    int ID = Convert.ToInt32(this.Page.Request.QueryString["ItemID"].ToString());

                 SPListItem spNewItem = myList.Items.Add();

                    spWeb.AllowUnsafeUpdates = true;

                    string fileName1 = System.IO.Path.GetFileName(“file Name”);//Mention File name

                    if (fileName1 != "")

                    {

                        Stream fStream = firstinputFile.PostedFile.InputStream;

                        byte[] contents = new byte[fStream.Length];

                        fStream.Read(contents, 0, (int)fStream.Length);

                        fStream.Close();

                        fStream.Dispose();

                        SPAttachmentCollection attachments = myNewItem.Attachments;

                        fileName1 = Path.GetFileName(firstinputFile.PostedFile.FileName);

                        attachments.Add(fileName1, contents);

                        spNewItem.Update();

               }

});