Error checking

Since error 1004 is not trappable (or not in the list of trappable errors), How do I check to see if val is in the named range price?
This is the line I am having problems with.

If WorksheetFunction.IsError(WorksheetFunction.VLookup(val, Range("price"), 2, False)) = True Then

Private Sub Itemnum_AfterUpdate()

On Error Resume Next

Dim val As String
With userforms1
 

    val = Itemnum.Value

    'check to see if val is in range price
    'if not reset
    If WorksheetFunction.IsError(WorksheetFunction.VLookup(val, Range("price"), 2, False)) = True Then
        Itemnum.Value = ""
        MsgBox ("You have entered an invalid Item Number, Please try again.")
        Itemnum.SetFocus
        Exit Sub
    Else
        'populate descrption
        desc.Value = WorksheetFunction.VLookup(val, Range("price"), 2, False)
    End If
    '  get priceing
    If tog.Value = "True" Then
        price.Value = Format(WorksheetFunction.VLookup(val, Range("price"), 6, False), dformat)
    Else
        price.Value = Format(WorksheetFunction.VLookup(val, Range("price"), 5, False), dformat)
    End If

End With
End Sub