FileInfo _fi = new FileInfo(files[0]);
                if (_fi.Exists)
                {
                    if (_fi.Extension.ToLower() == ".[ExtentionName]")
                    {
                        fi = _fi;
                        tbxFileName.Text = _fi.FullName;
                    }
                }
            }
        }

        private void fileSelector_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.All;
        }