Set your status field to have an auto-enter calculation. Uncheck the box that says "do not replace if field contains value"
The calculation is simple:
If ( IsEmpty( Invoices::Invoice Number ; "" ; "Invoiced" )
Since you reference the Invoice Number field in the calculation, anytime THAT field changes, the auto-entry of this field will now change.
Thank you for the reply. I tried putting the calculation above but I says There are to many parameters in this function.
Seems I missed a ) on the phone after the field name.
If ( IsEmpty( Invoices::Invoice Number ) ; "" ; "Invoiced" )
Thank you so much Mike. I appreciate it.