Can anyone help me please

The bit of code below outputs 30 text boxes onto a page and takes about 25
seconds to do.
This is a trial sample of something I am trying to develop.
My 2 Questions are
1) Is there a limit to the number of text boxes you can output to a
document, and
2) If not, how can I speed this up. The application I am working on
potentially has thousands of text boxes to output over 10s of pages.

Many thanks
Phil

Option Explicit

Function DrawTextBoxs(NoBoxes As Integer)

   Dim i As Long

   Dim TopCorner As Long

   Dim LeftCorner As Long

   For i = 1 To NoBoxes

       If LeftCorner = 0 Then

           LeftCorner = 20

       Else

           LeftCorner = LeftCorner + 150

       End If

       If TopCorner = 0 Then

           TopCorner = 10

       End If

       If LeftCorner > 500 Then

           LeftCorner = 20

           TopCorner = TopCorner + 100

       End If

       ActiveDocument.Shapes.AddTextbox(msoTextOrientationHorizontal,
LeftCorner, TopCorner, 100, 80).Select

       Selection.ShapeRange.Select

       With Selection.ShapeRange

           .TextFrame.MarginLeft = 0#

           .TextFrame.MarginRight = 0#

           .TextFrame.MarginTop = 0#

           .TextFrame.MarginBottom = 0#

           .Fill.Visible = msoTrue

           .Fill.Solid

           .Fill.ForeColor = i * 3000

           .Fill.Transparency = 0#

           .Line.Transparency = 0#

           .Line.Visible = msoTrue

           If i / 2 = i \ 2 Then

               .Line.DashStyle = msoLineSolid

               .Line.Style = msoLineSingle

               .Line.Weight = 5

           Else

               .Line.DashStyle = msoLineSquareDot

               .Line.Style = msoLineSingle

               .Line.Weight = 2

           End If

           .Line.Style = msoLineSingle

           .Line.ForeColor = 1500000 - (i * 2000)

       End With

       With Selection.Font

           If i / 2 = i \ 2 Then

               .NameAscii = "Arial"

           Else

               .NameAscii = "Comic Sans"

           End If

           .Size = 10 + i \ 2

           .Bold = True

           .Italic = False

           .Underline = True

           .UnderlineColor = wdColorAutomatic

           .StrikeThrough = False

           .DoubleStrikeThrough = False

           .Outline = False

           .Emboss = False

           .Shadow = False

           .Hidden = False

           .SmallCaps = False

           .AllCaps = False

           .Color = 2000 + (i * 3500)

           .Engrave = False

           .Superscript = False

           .Subscript = False

           .Spacing = 0

           .Scaling = 100

           .Position = 0

           .Kerning = 0

           .Animation = wdAnimationNone

       End With

                                                         ' Center

       Selection.ParagraphFormat.Alignment = wdAlignParagraphCenter

       Selection.TypeText Text:="This is Text Box " & i

       Selection.Collapse

   Next i

End Function

Sub Test()

'

' Test Macro

' Macro created 07/12/2004

'

Call DrawTextBoxs(30)

End Sub