Validation of entered value in an existing table
As start of a returns process, I'd like the user to enter a Sales Order Number and Customer Number.
The expression manager should:
1) check if the entered value for the Sales Order exists in the table of Sales Orders
2) check if the entered value of Customer Number exists in the Customer master data
3) check if the combination of two values is valid
Is the expression manager the right tool for this? If so, is the function 'Exist' the right function? I do no quiet understand the syntax.