# RequestCheckFormFieldCallback Function

> Callback function for requesting a CheckFormField.

- **Product:** TX Text Control .NET Server
- **Section:** Reference
- **Kind:** Function
- **Path:** TX Text Control .NET Server > Reference > JavaScript API > RequestCheckFormFieldCallback Function
- **284 words**
- **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/javascript/requestcheckformfieldcallback/
- **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/javascript/requestcheckformfieldcallback/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/javascript/requestcheckformfieldcallback/llms-full.txt

---

### Description

Callback function for requesting a CheckFormField.

### Syntax

```javascript
function(<CheckFormField> checkFormField)
```

### Examples

The following example demonstrates `RequestCheckFormFieldCallback` in a practical document-editing workflow. Callback function for requesting a CheckFormField.

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

function requestCheckFormFieldCallback(checkFormField) {
    console.log("check form field:", checkFormField);
}

TXTextControl.textParts.getMainText(function(mainText) {
    const formFields = mainText.formFields;
    formFields.addCheckFormField(true, requestCheckFormFieldCallback, onTxError);
}, onTxError);
```

---

## Nearby

- **Previous:** [RequestChangeKindCallback Function](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/javascript/requestchangekindcallback/llms-full.txt)
- **Next:** [RequestCollectionElementCallback Function](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/javascript/requestcollectionelementcallback/llms-full.txt)