#       Fossil checkout is present, valid, and is actually a directory.
  #       There are no arguments.  Script errors will be raised if any of
  #       the checks fail.
  #
  proc verifyCheckoutDirectory {} {
    variable checkoutDirectory

    #
    # NOTE: Setup example directory paths for use in the error message
    #       that may be produced by this procedure.  Since these values
    #       are specific to the platform, they are setup in advance.
    #       These values are NOT used to interact with the file system.
    #
    if {[isWindows]} then {
      set repositories C:/repositories
      set checkouts C:/checkouts
    } else {
      set repositories ~/repositories
      set checkouts ~/checkouts
    }

      set fileNames [$dialog -create FileNames]

      $sender Items.Clear
      $sender Items.AddRange $fileNames

      set list [object create -alias StringList $fileNames]

      set $varName [$list ToString]
    } else {
      set $varName [tk_getOpenFile -multiple true]
    }
  }

  #

  #
  # <internal>
  proc setupWinFormsUserInterface {} {
    variable argumentData
    variable widgets

    object load -import System.Windows.Forms

    ###########################################################################

    set form [object create -alias Form]
    set widgets(0) $form

    $form Text "Package Uploader Client"
    $form MaximizeBox false
    $form AutoSize true

  #
  # <internal>
  proc setupTkUserInterface {} {
    variable widgets

    package require Tk
    catch {console show}
    catch {wm withdraw .}

    ###########################################################################

    catch {wm withdraw .}; set toplevel [toplevel .uploader]
    set toplevel [toplevel .uploader]
    set widgets(toplevel) $toplevel

    wm title $toplevel "Package Uploader Client"
    wm minsize $toplevel 250 0

    wm protocol $toplevel WM_DELETE_WINDOW \
        [namespace code [list handleFormClosedEvent]]