这个层存在吗？

Option Explicit
Dim response As Integer  'Yes/No..
Dim BlockPoint As Variant 'First Insertion point..
Dim RMblock As AcadBlockReference 'Inserted Revision Marker block..
Dim AttribZ As Variant
Dim CountX As Integer 'Counter..
Dim RMlayer As AcadLayer
' FINISHED..
Private Sub FINISHEDbtn_Click()
Unload Me
End Sub
' HELP..
Private Sub HELPbtn_Click()
'Dim retval
'retval = Shell("C:\Program Files\Internet Explorer\IExplore.exe ""X:\CAD_Tools\Help\RM_help.html""", vbMaximizedFocus)
End Sub
Private Function DoesLayerExist() As AcadLayer
Dim LayerName As String
Dim objLayer As AcadLayer
LayerName = "LSC-REVISIONS_" & revnumCOMBO.Text
      
      For Each objLayer In ThisDrawing.Layers
            If UCase(objLayer.Name) = UCase(LayerName) Then
                  DoesLayerExist = True
                  RMlayer = objLayer
                  MsgBox "Layer Does Exist: " & objLayer
                  Exit Function
            End If
      Next objLayer
      
      DoesLayerExist = False
      MsgBox "Layer Does Not Exist: " & objLayer
      RMlayer = ThisDrawing.Layers.Add("LSC-REVISIONS_" & revnumCOMBO.Text)
      RMlayer.Plottable = False
End Function
'********************************************
'******** INSERT MARKERS ***********
'********************************************
Private Sub AddMArkersBTN_Click()
revmarkform.Hide
' Check if input is present..
If revnumCOMBO.Text = "" Then
    MsgBox "Please enter or select the Revision Number..", vbExclamation, "Revision Markers.."
    Exit Sub
End If
If revdateTXT.Text = "" Then
    MsgBox "Please enter or select the revision date..", vbExclamation, "Revision Markers.."
    Exit Sub
End If
'Get pick point..
'Error Test for GetPoint method..
On Error Resume Next
TryAgain:
BlockPoint = ThisDrawing.Utility.GetPoint(, vbCr & "Pick the first insertion point for the Revision Marker..")
'Insert block..
    Set RMblock = ThisDrawing.PaperSpace.InsertBlock(BlockPoint, "P:\CAD_Blocks\PaperSpace Stuff\Program Blocks\Revision Marker.dwg", 1#, 1#, 1#, 0)
    RMblock.Layer = DoesLayerExist(objLayer.Name)
AttribZ = RMblock.GetAttributes ' Get Block attributes..
                
For CountX = LBound(AttribZ) To UBound(AttribZ)
    Select Case AttribZ(CountX).TagString
    Case "REV_NUM_INDICATOR"
        AttribZ(CountX).TextString = UCase(revnumCOMBO.Text)
    Case "COMMENTS_DATE"
        AttribZ(CountX).TextString = revdateTXT.Text
    End Select
Next CountX
ErrHndlr:
    If Err.Number  0 Then
        If Err.Number = -2145320928 Then
            GoTo END_DO
        End If
        Err.Clear
        GoTo TryAgain
    End If
    On Error GoTo ErrHndlr
'*******************************
'** Start the point pick loop **
'*******************************
Do
CountX = CountX + 1  'Add 1 to the counter..
' Error Test for GetPoint method..
'On Error Resume Next
TryAgain2:
BlockPoint = ThisDrawing.Utility.GetPoint(, vbCr & "Pick the insertion point for the next Revision Marker..")
'Insert block..
    Set RMblock = ThisDrawing.PaperSpace.InsertBlock(BlockPoint, "P:\CAD_Blocks\PaperSpace Stuff\Program Blocks\Revision Marker.dwg", 1#, 1#, 1#, 0)
    RMblock.Layer = DoesLayerExist(objLayer.Name)
AttribZ = RMblock.GetAttributes ' Get Block attributes..
                
For CountX = LBound(AttribZ) To UBound(AttribZ)
    Select Case AttribZ(CountX).TagString
    Case "REV_NUM_INDICATOR"
        AttribZ(CountX).TextString = UCase(revnumCOMBO.Text)
    Case "COMMENTS_DATE"
        AttribZ(CountX).TextString = revdateTXT.Text
    End Select
Next CountX
ErrHndlr2:
    If Err.Number  0 Then
        If Err.Number = -2145320928 Then
            GoTo END_DO
        End If
        Err.Clear
        GoTo TryAgain2
    End If
    'On Error GoTo ErrHndlr2
    On Error GoTo END_DO 'Exit the loop if ENTER or another key is hit (basically an error)..
    
Loop
'*******************************
'******** End the loop *********
'*******************************
END_DO:
revmarkform.Show
End Sub
'********************************************
'******** INSERT MARKERS ***********
'********************************************
Private Sub revdateTXT_DblClick(ByVal Cancel As MSForms.ReturnBoolean)
revdateTXT.Text = Format(Date, "DD/MM/YYYY")
End Sub
'********************************************
'*************** FORM LOAD ******************
'********************************************
Private Sub UserForm_Initialize()
ThisDrawing.ActiveSpace = acPaperSpace
With revnumCOMBO
    .AddItem ("P2")
    .AddItem ("P3")
    .AddItem ("P4")
    .AddItem ("P5")
    .AddItem ("P6")
    .AddItem ("P7")
    .AddItem ("P8")
    .AddItem ("P9")
    .AddItem ("P10")
    .AddItem ("C1")
    .AddItem ("C2")
    .AddItem ("C3")
    .AddItem ("C4")
    .AddItem ("C5")
    .AddItem ("C6")
    .AddItem ("C7")
    .AddItem ("C8")
    .AddItem ("C9")
    .AddItem ("C10")
    .AddItem ("AB")
End With
End Sub
'********************************************
'*************** FORM LOAD ******************
'********************************************
'********************************************
'*************** FORM UNLOAD ****************
'********************************************
Private Sub UserForm_QueryClose(Cancel As Integer, closemode As Integer)
response = MsgBox("Are you sure you've finished with the 'Revision Markers'?..", vbQuestion + vbYesNo, "End the Program..")
    If response = vbNo Then
    Cancel = 1
    End If
    If response = vbYes Then
        Unload Me
    End If
End Sub
'********************************************
'*************** FORM UNLOAD ****************
'********************************************