# Javascript: Selection.setUnderline Method

> Sets the underlining styles for the selected text.

- **Product:** DS Server
- **Section:** Reference
- **Kind:** Method
- **Introduced:** 26.0
- **Path:** DS Server > Reference > JavaScript API > Javascript: Selection.setUnderline Method
- **333 words**
- **Web URL:** https://docs.textcontrol.com/ds-server/reference/javascript/selection/setunderline-method/
- **LLMs URL:** https://docs.textcontrol.com/ds-server/reference/javascript/selection/setunderline-method/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/ds-server/reference/javascript/selection/setunderline-method/llms-full.txt

---

### Description

Sets the underlining styles for the selected text.

### Syntax

```javascript
<void> Selection.setUnderline(<FontUnderlineStyle> underline, [<EmptyRequestCallback> callback], [<ErrorCallback> errorCallback])
```

### Parameters

| Parameter | Description |
|---|---|
| underline | The underlining styles for the selected text. |
| callback | Optional. Is called when the operation completed. |
| errorCallback | Optional. Is called when the operation failed with an error. |

### Examples

The following example demonstrates `Selection.setUnderline` in a practical document-editing workflow. It sets the underlining styles for the selected text.

```javascript
function onTxError(error) {
    console.error("TX Text Control error:", error.msg);
    error.handled = true;
}

TXTextControl.selection.setUnderline(
    TXTextControl.FontUnderlineStyle.Single,
    function() {
        console.log("set underline completed.");
    },
    onTxError
);
```

---

## Nearby

- **Previous:** [Javascript: Selection.setTextBackColor Method](https://docs.textcontrol.com/ds-server/reference/javascript/selection/settextbackcolor-method/llms-full.txt)
- **Next:** [Javascript: Selection.shrinkFont Method](https://docs.textcontrol.com/ds-server/reference/javascript/selection/shrinkfont-method/llms-full.txt)