Message popup while approving PO

Hello All,

We have a new requirement to add a DFF field at PO line level which will capture proposed unit price(value will always be greater than 0).

By default,zero is being populated. If user fails to update that DFF,then it should throw an message stating that field value is zero and should not proceed further.

Im using personalization with below conditions

Condition

Trigger EVent : WHEN VALIDATE RECORD

Trigger Object : PO APPROVE

Condition : :PO_LINES.ATTRIBUTE1=0

Processing Mode : Only in Query Mode

Action

Message

Message type : ERROR

Message text :

='Proposed Unit Price is required for line number : '||(select rtrim (xmlagg (xmlelement (e, line_num || ',')).extract ('//text()'), ',') line_num