Age calculation function in vb.net

I know this is a really simple task but i needed it in a project and i found a working function on www.freevbcode.com so i decided to publish it here too

Public Function GetAge(ByVal Birthdate As System.DateTime, _
    Optional ByVal AsOf As System.DateTime = #1/1/1700#) _
    As String

        'Don't set second parameter if you want Age as of today

        'Demo 1: get age of person born 2/11/1954
        'Dim objDate As New System.DateTime(1954, 2, 11)
        'Debug.WriteLine(GetAge(objDate))

        'Demo 1: get same person's age 10 years from now
        'Dim objDate As New System.DateTime(1954, 2, 11)
        'Dim objdate2 As System.DateTime
        'objdate2 = Now.AddYears(10)
        'Debug.WriteLine(GetAge(objDate, objdate2))

        Dim iMonths As Integer
        Dim iYears As Integer
        Dim dYears As Decimal
        Dim lDayOfBirth As Long
        Dim lAsOf As Long
        Dim iBirthMonth As Integer
        Dim iAsOFMonth As Integer

        If AsOf = "#1/1/1700#" Then
            AsOf = DateTime.Now
        End If
        lDayOfBirth = DatePart(DateInterval.Day, Birthdate)
        lAsOf = DatePart(DateInterval.Day, AsOf)

        iBirthMonth = DatePart(DateInterval.Month, Birthdate)
        iAsOFMonth = DatePart(DateInterval.Month, AsOf)

        iMonths = DateDiff(DateInterval.Month, Birthdate, AsOf)

        dYears = iMonths / 12

        iYears = Math.Floor(dYears)

        If iBirthMonth = iAsOFMonth Then
            If lAsOf < lDayOfBirth Then
                iYears = iYears - 1
            End If
        End If

        Return iYears
    End Function

As you can see it's really simple, just cut & paste in your project, it works fine and you don't loose 10 minutes of work