Update all fields in Word, including headers and footers (Edit)

At 11th November last year, I post a piece of code to update all fields in a Word document. Some people respond that it didn't work. Well, I tried, and it seems that's true.
Today, I rewrote a new piece of code I found, and that seems to work fine. I created an extension method for the Word.Document object that does the trick.

 _
Sub UpdateAllFiels(ByVal doc As Word.Document)

Dim section As Word.Section
Dim myRange As Word.Range
Dim myHF As Word.HeaderFooter

doc.Fields.Update()

For Each section In doc.Sections

 For Each myHF In section.Headers
  myRange = myHF.Range

  For Each aField In myRange.Fields
   If aField.Type = Word.WdFieldType.wdFieldDocProperty Then
    aField.Update()
   End If
  Next aField

 Next myHF

 For Each myHF In section.Footers
  myRange = myHF.Range

  For Each aField In myRange.Fields
   If aField.Type = Word.WdFieldType.wdFieldDocProperty Then
    aField.Update()
   End If
  Next aField

 Next myHF

Next section

End Sub

So, now I am able to update all fields easily in my document. In my Word Add-on, I created a own ribbon tab, I placed a button on it, which does the following:

Globals.ThisAddIn.Application.ActiveDocument.UpdateAllFiels()

Note: Extension methods is supported on .NET framework 3.5 or higher

Edit: A little fix: 'doc.Fields.Update()' added to the code. This is the regular Word Update All Fields function (so without doing Headers and Footers).