# Expression
**YouTube:** [How to Configure and Use Expression Functions in Sale Bill?](https://www.youtube.com/watch?v=oOsuVpBZWEw)
## How to Configure and Use Expression Functions in Sale Bill?
In this tutorial, we’ll demonstrate how to **set default expressions for generating a sales bill** in **Logic ERP**, allowing fields like **Remarks** to populate automatically based on user-defined expressions.
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### **Access Sales Voucher Configuration**
* Open the **Sales Voucher Configuration** window.
* Select the **relevant billing series**.
* Under **"Other Settings - 1"**, click on **"Other Settings"**.
* Then navigate to **"Defaults - 2"**.
* Locate the option labeled: “**Expression”**.
* Here, you can define **custom expressions** using the available field list.
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### **Create a Default Expression**
* Let’s create a default expression for the **Remarks One** field.
* In the expression editor, combine fields such as:
* **Transport Mode**
* **Vehicle Number**
* Save the configuration after setting the expression.
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### Functionality in the Billing Process
* Navigate to the **Sale Bill** window.
* Enter the **Transport Mode** and **Vehicle Number** in Other Details Column.
* Proceed to **save the bill**.
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### Observe the Applied Changes
* Reopen the saved bill.
* Navigate to the **Other Details** section.
* Observe that the **Remarks One** field is **automatically populated** with the values entered for transport mode and vehicle number.
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### **Conclusion**
Using default expressions in Logic ERP allows for **automated data entry**, reducing manual effort and ensuring consistency across sales bills.
