Thanks for the reply Samuel, i wrote a simple example on weborder 19.1 to give you some context

on Order.wo change the object oOrderHeaderOrder_Number to:

Code:
        Use Orderb.wo

        Object oOrderHeaderOrder_Number is a cWebForm
            Entry_Item OrderHeader.Order_Number
            Set piColumnSpan to 3
            Set piColumnIndex to 0
            Set psLabel to "Order Number:"
            Set peLabelAlign to alignRight
            Set pbServerOnBlur to True
            
            Procedure OnBlur
                Forward Send OnBlur
                
                Send Popup to oOrderB Self
                
            End_Procedure
            
        End_Object
drop the orderb.wo in same directory

Orderb.wo

thanks again for your time