---
{
	"_label": "Custom Script: Fetch Values from Master"
}
---
To pull a value of a link on selection, use the `add_fetch` method.

	add_fetch(link_fieldname, source_fieldname, target_fieldname)

### Example

You create Custom Field **VAT ID** (`vat_id`) in **Customer** and **Sales Invoice** and want to make sure this value gets updated every time you select a Customer in a Sales Invoice.

Then in the Sales Invoice Custom Script, add this line:

	cur_frm.add_fetch('customer','vat_id','vat_id')
	

---
See: [How to create a custom script](!docs.dev.custom_script.html)