var = App.Do( Environment, 'GetString', {   
        'DefaultText': strMyLayer,
        'DialogTitle': 'Get String',
        'Prompt': 'Enter the Layer Name',
        'MaxLength': 50,
        'GeneralSettings': {
           'ExecutionMode': App.Constants.ExecutionMode.Interactive
           }
        })

    strMyLayer= var[ 'EnteredText' ]
    x = var[ 'OKButton' ]