--- title: "Basic External Form Process" slug: "basic-external-form-process" description: "Learn how to use the External Form step to pass and retrieve form data through HTML methods or service calls." tags: ["JavaScript", "IIS", "External Data", "HTML"] status: "update" updated: 2026-09-10T14:41:26Z published: 2026-09-10T14:41:26Z canonical: "documentation.decisions.com/basic-external-form-process" --- > ## Documentation Index > Fetch the complete documentation index at: https://documentation.decisions.com/llms.txt > Use this file to discover all available pages before exploring further. # Basic External Form Process ## Overview The **External Form** step can interact with Forms by using HTML methods or service calls. This method can also pass data into and retrieve data from an External Form. WarningCross-origin resource sharing requires additional configuration. By default, requests originating from a different domain will be blocked. As a workaround, add an HTTP protocol reference by visiting the [Forum](https://support.decisions.com/forum/topic120-cors-workaround.aspx). --- ## Example The following example will demonstrate how to call an External Form in IIS. 1. In a code editor, enter the following code and save it as "TestForm.html" in a new Folder under **C:\inetpub\wwwroot\ExternalFormTestFolder**.Adding to the wwwroot Folder will require administrative permissions. ```markup
Decisions External Form Example
This web page is a simple HTML and javascript web page illustrating the use of Decisions flow engine using a completely custom build web
application to interact with the platform.
The following data were sent to this page from Decisions flow engine:
1.
2.
3.
Other Parameters:
In order to return to the Decisions flow engine you need to specify an "Outcome" to use in the callback url. The callback url should be composed
from the parameters in the list above and must include the following:
1. action=PostCustomFormDataToFlow
2. flowTrackingId = Use the value shown above
3. stepTrackingId = Use the value shown above
4. OutcomeName = value
5. Additional Data to Send (use name=value&)
Specify an outcome and click "Send to Decisions" when ready.
Outcome Name:
Additional Data: