# System Properties

Applications can request a named system property, which is currently limited to the device ID. The device ID, or nduid, is a 20-byte (160 bit) SHA-1 digest unique to each device.

Your application should not use the device ID to uniquely identify a given user. Because devices may be bought, sold, exchanged, or even serviced in a way that results in a user's device ID changing or being transferred to another user, user data and preferences should never be saved and restored on the basis of the device ID; you should implement your own account management system for this purpose.

## Method

This section describes the following method:

- Get

### Get

Requests the named system property, which is returned in a response object.

Required parameter:

- key

#### Parameters

Parameter | Type | Description
--- | --- | ---
key | string | Set to "com.palm.properties.nduid", which is the device's unique ID.

#### Return Handling

onSuccess

Attribute | Type | Description
--- | --- | ---
key | string | Set to the input key.
value | string | Set to value of the input key.

#### Example

>     this.controller.serviceRequest('palm://com.palm.preferences/systemProperties', {
>       method:"Get",
>       parameters:{"key": "com.palm.properties.nduid" },
>       onSuccess: function(response){}
>     });

## Sample Code

See Services Sample.