C# dialog.InitialDirectory จำค่าเดิมทั้งๆที่เปลี่ยนค่าไปแล้ว

void SetPicPath(TextBox txt)
        {
            string filter = "Image files (*.jpg, *.jpeg, *.jpe, *.jfif, *.png) | *.jpg; *.jpeg; *.jpe; *.jfif; *.png";
            using (OpenFileDialog dialog = new OpenFileDialog())
            { 
            dialog.Filter =filter ;
            dialog.InitialDirectory = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
                if (dialog.ShowDialog() == DialogResult.OK)
                {
                    System.Threading.Thread.Sleep(100);
                    using (SaveFileDialog dialog1 = new SaveFileDialog())
                    { 
                    dialog1.Filter = filter;
                    dialog1.InitialDirectory = _CLASS.Extened.PathFilePic;
                    dialog1.RestoreDirectory = true;
                    dialog1.FileName = System.IO.Path.GetFileName(dialog.FileName);
                    if (dialog1.ShowDialog() == DialogResult.OK)
                    { System.IO.File.Copy(dialog.FileName, dialog1.FileName, true); }

                    txt.Text = System.IO.Path.GetFileName(dialog1.FileName);
                    }

                }    
            }
            
        }