---
title: "Example - Check The Lookups Value"
url: "https://help.tabidoo.cloud/en/article/example-check-the-lookups-value"
language: "en"
last_updated: "2026-03-27T07:13:08.210Z"
---

# Example - Check The Lookups Value

Do you need to check while saving that the selected value in the lookup corresponds to a defined condition and notify the user in the pop-up window? Let's have a look at it!

### Example scenario

You are creating an **Order** and selecting a **Customer** from a lookup field.  
Before saving the record, you want to verify that the selected customer is **active**.  
If the customer is inactive, a warning message is displayed and the record is not saved.

This is useful when you want to prevent users from linking records that should no longer be used.

* * *

## Step 1: Include the required value in the lookup

In the source table used by the lookup (in this example, the **Customers** table), make sure the field you want to validate is available in the lookup value.

For example, if the Customers table contains a field such as:

-   **Active**
-   internal name: `active`

enable **Include in lookup selected value** for this field in the developer settings.

This allows you to access the value later in JavaScript through the lookup object.

* * *

## Step 2: Add JavaScript in **Before model save**

In the target table (in this example, **Orders**), open the advanced settings and add your JavaScript to **Before model save**.

We use **Before model save** because the validation should run only when the user saves the record.

* * *

## JavaScript example

```typescript
if (doo.model.customer.value && doo.model.customer.value.active === false) {
  doo.alert.showWarning(
    'Inactive customer',
    'The selected customer is inactive. Please choose another customer.'
  );
  doo.model.isValid = false;
} else {
  doo.model.isValid = true;
}
```

* * *

## How it works

`doo.model.customer.value`  
represents the selected record in the lookup field.

`doo.model.customer.value.active`  
reads the value of the `active` field from the selected customer.

`doo.model.customer.value.active === false`  
is the condition that checks whether the selected customer is inactive.

`doo.alert.showWarning(...)`  
displays a pop-up warning message to the user.

`doo.model.isValid = false`  
prevents the record from being saved.

`doo.model.isValid = true`  
allows the record to be saved if the condition is met.

* * *

## Result

When the user selects an inactive customer and tries to save the order, a warning is shown and the record is not saved.