Workflow: getting father requirement objects from Req_FieldChange

In WorkFlow, Script Editor

I am trying to implement to update a certain field of father requirement when a certain field of child requirement is changed.

I wrote a macro as below. however, I am trying to get the father requirement by using ReqFactory Item, i received an error message in the red marked parts that i need an object. coudl you please help me on this?

<CODE>

Sub Req_FieldChange(FieldName)
' On Error Resume Next

if FieldName = "RQ_REQ_STATUS" and Req_Fields (FieldName).value = "Passed" then
      Update_Father Req_Fields ("RQ_FATHER_NAME").value
end if
' On Error GoTo 0
End Sub

Public SubUpdate_Father (RQ_FATHER_ID)

' Get the requirement Factory.

Dim rFact 'As ReqFactory

Set rFact = TDConnection.ReqFactory
Dim father_req 'As Req
Set father_req = rFact.Item(RQ_FATHER_ID)
father_req .Field("RQ_USER_07").value = 5

End Sub