How do I automatically fill a field on a form

SH2010

On a form, based on Form no. 45 Sales List, I look up to pick order number. I want the corresponding customer number to be filled in automatically when I pick the sales order number.

RockWithNAV

Write this code on OnValidate Trigger of the Order No.

Customer.GET("Sell-to Customer No.");
CustomerNameVariable := Customer.Name;

mohana_cse06

You need to write code in Onvalidate trigger of OrderNumber field.
Get the Order and assign the Sell-to cystomer no. field

RockWithNAV

Write this code on OnValidate Trigger of the Order No.

Customer.GET("Sell-to Customer No.");
CustomerNameVariable := Customer.Name;

SH2010

Thanks hey it has worked.