# \_checkLandlineIsUnique

Check is a customers landline number is unique.

### Parameters

#### id

The id of the customer.

#### landline

The customers landline number.

### Example

```
FM_api('Customer_checkLandlineIsUnique', [
    'id' => '1', 
    'landline' => '02841753939'
    ]
);
```

### Result

#### On Success

```
{"ok":1}
```

#### On Failure

If the "id" parameter is not set or less than 1:

```
{"error":"invalid or missing parameter: id"}
```

If there's another Customer with the same Landline number:\
(The ID and name of that customer are returned in this result)

```
{"ok":0,"data":{"id":682785,"name":"A Test Customer"}}
```