MahApps LoginDialog

$Settings                          = [MahApps.Metro.Controls.Dialogs.LoginDialogSettings]::new()
    $Settings.ColorScheme              = "Accented"
    $Settings.DialogMessageFontSize    = "16"
    $Settings.DialogTitleFontSize      = "18"
    $Settings.NegativeButtonVisibility = "Visible"
    $Settings.DialogResultOnCancel     = "Affirmative"
    $Settings.UsernameWatermark        = "Username..."
    $Settings.PasswordWatermark        = "Password..."
    $Settings.UsernameCharacterCasing  = "Normal"
    $Settings.DefaultButtonFocus       = "Affirmative"
    $Settings.EnablePasswordPreview    = "True"

    $Global:DialogResults              = [MahApps.Metro.Controls.Dialogs.DialogManager]::ShowModalLoginExternal ($UI.Window,"Authentication","Enter your _adm credentials :",$Settings)