Need explanation about On Error Statement

[ybr_15]

Hi, I am still try to figuring out about this On Error Statement. I have a case in Debra Dalgleish post (http://www.contextures.com/xlDataVal10.html) about "Excel Data Validation Combo Box".
Here the code:

Option Explicit
' Developed by Contextures Inc.
' www.contextures.com
Private Sub TempCombo_KeyDown(ByVal _
        KeyCode As MSForms.ReturnInteger, _
        ByVal Shift As Integer)
    'Hide combo box and move to next cell on Enter and Tab
    Select Case KeyCode
        Case 9
            ActiveCell.Offset(0, 1).Activate
        Case 13
            ActiveCell.Offset(1, 0).Activate
        Case Else
            'do nothing
    End Select

End Sub

Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
Dim str As String
Dim cboTemp As OLEObject
Dim ws As Worksheet
Set ws = ActiveSheet
On Error GoTo errHandler

If Target.Validation.Type = 3 Then
Cancel = True
End If

Set cboTemp = ws.OLEObjects("TempCombo")
[COLOR=#ff0000]  On Error Resume Next[/COLOR]
  With cboTemp
    .ListFillRange = ""
    .LinkedCell = ""
    .Visible = False
  End With
[COLOR=#ff0000]On Error GoTo errHandler[/COLOR]
  If Target.Validation.Type = 3 Then
    Application.EnableEvents = False
    str = Target.Validation.Formula1
    str = Right(str, Len(str) - 1)
    With cboTemp
      .Visible = True
      .Left = Target.Left
      .Top = Target.Top
      .Width = Target.Width + 15
      .Height = Target.Height + 5
      .ListFillRange = ws.Range(str).Address
      .LinkedCell = Target.Address
    End With
    cboTemp.Activate
    'open the drop down list automatically
    Me.TempCombo.DropDown
  End If
  
[COLOR=#ff0000]errHandler:
  Application.EnableEvents = True
  Exit Sub[/COLOR]

End Sub

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim str As String
Dim cboTemp As OLEObject
Dim ws As Worksheet
Set ws = ActiveSheet

Set cboTemp = ws.OLEObjects("TempCombo")
[COLOR=#ff0000]  On Error Resume Next[/COLOR]
If cboTemp.Visible = True Then
  With cboTemp
    .Top = 10
    .Left = 10
    .ListFillRange = ""
    .LinkedCell = ""
    .Visible = False
    .Value = ""
  End With
End If

[COLOR=#ff0000]errHandler:
  Application.EnableEvents = True
  Exit Sub[/COLOR]

End Sub

The code with red higlight is my question.

1. Why the author using On Error Resume Next? Because I don't get error if I delete this statement
2. Why on errHandler: using Application.EnableEvents = True?
3. In the Private Sub Worksheet_SelectionChange(ByVal Target As Range), if I delete this statement (code below) no error occur. Why the author still using?:

[COLOR=#ff0000]errHandler:
  Application.EnableEvents = True
  Exit Sub[/COLOR]

Thanks...

 

[Gerald Higgins]

Err . . . have you considered asking Debra Dalgleish ?