# Javascript: ApplicationFieldCollection.add Method

> Inserts a new application field at the current input position.

- **Product:** DS Server
- **Section:** Reference
- **Kind:** Method
- **Introduced:** 28.0
- **Path:** DS Server > Reference > JavaScript API > Javascript: ApplicationFieldCollection.add Method
- **619 words**
- **Web URL:** https://docs.textcontrol.com/ds-server/reference/javascript/applicationfieldcollection/add-method/
- **LLMs URL:** https://docs.textcontrol.com/ds-server/reference/javascript/applicationfieldcollection/add-method/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/ds-server/reference/javascript/applicationfieldcollection/add-method/llms-full.txt

---

### Description

Inserts a new application field at the current input position.

### Syntax

```javascript
<void> ApplicationFieldCollection.add(<ApplicationFieldFormat> format, <string> typeName, <string> text, <string[]> parameters, [<RequestApplicationFieldCallback> callback], [<ErrorCallback> errorCallback])
```

### Parameters

| Parameter | Description |
|---|---|
| format | Specifies the format of the field. The format depends on the application that supports the field. It can be ApplicationFieldFormat.MSWord or ApplicationFieldFormat.HighEdit. |
| typeName | Specifies the type name of the field. For example the type name of a Microsoft Word MergeField is MERGEFIELD. |
| text | Specifies the visible text of the field. |
| parameters | Specifies an array of strings which are the field's parameters. The order and format of the strings depend on the field's format. For example a Microsoft Word MergeField has the following format: MERGEFIELD FieldName \[switches\]. In this case the first string of the array is the FieldName and the following strings are possible switches. If a field has no parameters, null can be specified. |
| callback | Optional. Receives the added ApplicationField. |
| errorCallback | Optional. Is called when the operation failed with an error. |

### Examples

The following example inserts a Microsoft Word merge field for a customer name and inspects the live field returned by the add callback.

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

TXTextControl.textParts.getMainText(function(mainText) {
    mainText.applicationFields.add(
        TXTextControl.ApplicationFieldFormat.MSWord,
        "MERGEFIELD",
        "CustomerName",
        ["CustomerName", "\\* MERGEFORMAT"],
        function(applicationField) {
            applicationField.getID(function(id) {
                console.log("Customer merge field added with ID:", id);
            }, onTxError);
        },
        onTxError
    );
}, onTxError);
```

---

## Nearby

- **Previous:** [ApplicationFieldCollection Object](https://docs.textcontrol.com/ds-server/reference/javascript/applicationfieldcollection/llms-full.txt)
- **Next:** [Javascript: ApplicationFieldCollection.getItem Method](https://docs.textcontrol.com/ds-server/reference/javascript/applicationfieldcollection/getitem-method/llms-full.txt)