Variable is crossing different events - vba

Question

Apologies for the vague title, but here is my issue. I have a form that has several select lists and associated text boxes. Basically the way it works is if you select a name from the first list, an AfterUpdate event is triggered to query the DB to see if the Eng_ID and Person_ID already exist in the table. If so, then delete that row then insert the updated row. If there is not any records, then just insert the data. The problem is that when I click a name in the first list, then move to the second list, what's happening is that the the Person_ID of the first list is used for the DLookup query, then it delets the record, then inserts the record of the new person I selected in a different listbox. The code is below: Thanks in advance
' Add/Remove Participant 1
Private Sub lstPar1_AfterUpdate()
Dim n As Integer
Dim strCriteria As String
Dim strSQL As String
With Me.lstPar1
For n = .ListCount - 1 To 0 Step -1
strCriteria = "Eng_ID = " & Nz(Me.Eng_ID, 0) & " And Person_ID = " & .ItemData(n)
If .Selected(n) = False Then
' If a person has been deselected, then delete row from table
If Not IsNull(DLookup("Eng_ID", "tblEngParRole", strCriteria)) Then
strSQL = "DELETE * FROM tblEngParRole WHERE " & strCriteria
CurrentDb.Execute strSQL, dbFailOnError
End If
Else
' If a person has been selected, then insert row into the table
If IsNull(DLookup("Eng_ID", "tblEngParRole", strCriteria)) Then
strSQL = "INSERT INTO tblEngParRole (Eng_ID, Person_ID, ParticipantNumber, Role)" & "VALUES(" & Me.Eng_ID & "," & .ItemData(n) & "," & 1 & ",'" & Me.txtParRole1.Value & "' )"
CurrentDb.Execute strSQL, dbFailOnError
End If
End If
Next n
End With
End Sub
' Add/Remove Participant 2
Private Sub lstPar2_AfterUpdate()
Dim n As Integer
Dim strCriteria As String
Dim strSQL As String
With Me.lstPar2
For n = .ListCount - 1 To 0 Step -1
strCriteria = "Eng_ID = " & Nz(Me.Eng_ID, 0) & " And Person_ID = " & .ItemData(n)
If .Selected(n) = False Then
' If a person has been deselected, then delete row from table
If Not IsNull(DLookup("Eng_ID", "tblEngParRole", strCriteria)) Then
strSQL = "DELETE * FROM tblEngParRole WHERE " & strCriteria
CurrentDb.Execute strSQL, dbFailOnError
End If
Else
' If a person has been selected, then insert row into the table
If IsNull(DLookup("Eng_ID", "tblEngParRole", strCriteria)) Then
strSQL = "INSERT INTO tblEngParRole (Eng_ID, Person_ID, ParticipantNumber, Role) " & "VALUES(" & Me.Eng_ID & "," & .ItemData(n) & "," & 2 & ",'" & Me.txtParRole2.Value & "' )"
CurrentDb.Execute strSQL, dbFailOnError
End If
End If
Next n
End With
End Sub
Using this image, if I select Daniel and enter his role, then the eng_ID, Person_ID, ParticipantNumber and Role are entered into the database as 130, 118, 1, Collaborator.
If I select Kristin, it deletes Daniel becuause it's still using Person_ID of 118 instead of hers which is 134, and since there is a corresponding record, it delets Daniel then adds Kristin.

Answer 1

I don't have Access to test this with, but it seems like you need to separate Participant1 records from Participant2 records when you perform your DLookups.
Also you can generalize your code by pulling the common parts into a separate sub.
Private Sub lstPar1_AfterUpdate()
CheckParticipant Me.lstPar1, 1, Me.txtParRole1.Value
End Sub
Private Sub lstPar2_AfterUpdate()
CheckParticipant Me.lstPar2, 2, Me.txtParRole2.Value
End Sub
Sub CheckParticipant(objList As Object, participantNum As Long, role As String)
Dim n As Integer
Dim strCriteria As String
Dim strSQL As String
With objList
For n = .ListCount - 1 To 0 Step -1
strCriteria = "Eng_ID = " & Nz(Me.Eng_ID, 0) & " And Person_ID = " & .ItemData(n) & _
" And ParticipantNumber=" & participantNum
strSQL = ""
If Not .Selected(n) Then
' If a person has been deselected, then delete row from table
If Not IsNull(DLookup("Eng_ID", "tblEngParRole", strCriteria)) Then
strSQL = "DELETE * FROM tblEngParRole WHERE " & strCriteria
End If
Else
' If a person has been selected, then insert row into the table
If IsNull(DLookup("Eng_ID", "tblEngParRole", strCriteria)) Then
strSQL = "INSERT INTO tblEngParRole (Eng_ID, Person_ID, ParticipantNumber, Role)" & _
" VALUES(" & Me.Eng_ID & "," & .ItemData(n) & "," & participantNum & _
",'" & role & "' )"
End If
End If
If Len(strSQL) > 0 Then CurrentDb.Execute strSQL, dbFailOnError
Next n
End With
End Sub