> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Step 9. Configure business rules

> Add business rules to validate and normalize extracted field values — adjust doctor IDs with regex and check sick note validity with script rules.

With the Extraction Rules activities configured, add business rules to validate and normalize the field values.

## Adjust the doctor's ID

Adjust the **Doctor ID** field properties to clean up OCR errors and unwanted characters from the pre-recognition results. After the field region is found, a regular expression in the field properties re-extracts the data and removes OCR noise.

<Steps>
  <Step title="Open the Doctor ID field settings">
    1. Click the skill name and go to the **Fields** tab.
    2. Expand the "Doctor" group and open the "Doctor ID" field settings by clicking the settings icon next to it.
  </Step>

  <Step title="Add a regular expression">
    1. In the **Value** section of the field properties, click the add icon next to the **Regular expression** option.
    2. Paste the following expression into the **Regular Expression Editor**:

       ```
       [0-9]{1}[\/.-]{1}[0-9]{5}[\/.-]{1}[0-9]{2}[\/.-]{1}[0-9]{3}
       ```

    <Note>
      This editor uses common notation that differs from the notation used in the Extraction Rules Activity Editor. For more information, click **Syntax help** in the **Regular Expression Editor**.
    </Note>
  </Step>

  <Step title="Save the changes">
    Click **Save** to close the **Regular Expression Editor**, and then click **Save** again to close the field properties.
  </Step>
</Steps>

## Check whether the sick note is valid

A patient must receive a sick note within 3 days of the sickness start date. In field terms: the issue date must be no more than 3 days after the start date. Use a script rule to enforce this constraint.

<Steps>
  <Step title="Open the New Rule dialog">
    Click the add icon under the data form. The **New Rule** dialog opens.

    <Note>
      If you don't see the add icon, switch to the **Reference** section above the document image.
    </Note>
  </Step>

  <Step title="Configure the rule type and fields">
    1. Select **Advanced Script Rule** and click **Next**.
    2. Rename the rule to "Check validity".
    3. Select the "Start Date" and "Date" fields in the list of fields.
    4. Click **Next**.
  </Step>

  <Step title="Add the validity script">
    Paste the following script in the script editor:

    ```javascript theme={null}
    // Create variables for all the fields you're going to access
    var startField = Context.GetField("Start Date") ;
    var dateField = Context.GetField("Date");

    if (dateField && dateField.Value && startField && startField.Value)
    {
       var date = dateField.Value;
       var startDate = startField.Value;

       //Calculate the earliest possible start date
       date.setDate(date.getDate() - 3);

       if (startDate < date)
       {
           Context.CheckSucceeded = false;
           Context.ErrorMessage = "The sick note was issued too late";
       }
    }
    ```

    Click **Save** and examine how the rule works on different documents in the set. To check how the rule handles errors, enter test values in the fields on the data form manually — the rule re-applies each time you change the field value.
  </Step>
</Steps>

## Check the sick leave duration

Calculate the sick leave duration from the start and end dates. If the document already specifies a duration, the rule verifies it matches. If not, the rule fills the duration field with the calculated value.

<Steps>
  <Step title="Open the New Rule dialog">
    Click the add icon under the data form to create a rule.
  </Step>

  <Step title="Configure the rule type and fields">
    1. Select **Advanced Script Rule** and click **Next**.
    2. Rename the rule to "Check duration".
    3. Select the "Start Date", "End Date", and "Duration" fields in the list of fields. Select the fields in both columns — the rule both reads field values and corrects them if necessary.
    4. Click **Next**.
  </Step>

  <Step title="Add the duration script">
    Paste the following script in the script editor:

    ```javascript theme={null}
    // Create variables for all the fields you're going to access
    var startField = Context.GetField("Start Date") ;
    var endField = Context.GetField("End Date");
    var durationField = Context.GetField("Duration");

    var startDate = startField.Value;
    var endDate = endField.Value;

    //Check if the "Start Date" and "End Date" fields were found on the document
    if (endField && endDate && startField && startDate)
    {
       //Calculate the sick leave duration
       var length = (1 + (endDate.getTime() - startDate.getTime()) / 3600000 / 24);

       //If the duration field was not found or could not be parsed as a number, pass the calculated value to the field
       if (!durationField.Value)
           durationField.Value = length; 

       //If the duration field was found, compare its value with the calculated duration
       else if (durationField.Value != length)
       {
           Context.CheckSucceeded = false;
           Context.ErrorMessage = "The value of the \"Duration\" field does not match the actual sick leave duration";
           durationField.AddSuggestion(length.toString());
       }
    }
    ```

    Click **Save** and examine how the rule works on different documents in the set. To check how the rule handles errors, enter test values in the fields on the data form manually — the rule re-applies each time you change the field value.
  </Step>
</Steps>

## What's next

<CardGroup cols={2}>
  <Card title="Step 10. Test and publish the skill" icon="arrow-right" href="/vantage/documentation/advanced-designer/tutorial/tutorial-step-10">
    Test the configured skill and publish it to the Vantage server.
  </Card>

  <Card title="Tutorial overview" icon="circle-info" href="/vantage/documentation/advanced-designer/tutorial/tutorial">
    Back to the tutorial introduction.
  </Card>
</CardGroup>