What code do i add below to warn me that the file already exists before overwriting the file?

    Option Explicit

    Dim swApp           As SldWorks.SldWorks

    Dim swModel         As SldWorks.ModelDoc2

    Dim swDraw          As SldWorks.DrawingDoc

    Dim swCustProp      As CustomPropertyManager

    Dim valOut          As String

    Dim resolvedValOut  As String

    Dim Filepath        As String

    Dim FileName        As String

    Dim swView          As SldWorks.View

    Sub main()

    Set swApp = Application.SldWorks

    Set swDraw = swApp.ActiveDoc

    ' Check to see if a drawing is loaded.

    If (swDraw Is Nothing) Or (swDraw.GetType <> swDocDRAWING) Then

    swApp.SendMsgToUser ("To be used for drawings only, Open a drawing first and then TRY!")

    ' If no model currently loaded, then exit

    Exit Sub

    End If

    Set swView = swDraw.GetFirstView

    Set swView = swView.GetNextView

    Set swModel = swView.ReferencedDocument

   ' Set swCustProp = swModel.Extension.CustomPropertyManager("")

   ' swCustProp.Get2 "Revision", valOut, resolvedValOut 'Change the custom property name here

    'Filepath = "C:\scans" ' Change File Path here

   Filepath = "v:\Die Correction\Midrand Transfers\Solids"
    Filepath = Filepath + "\"

    If Dir(Filepath) = "Die Correction\Midrand Transfers\Solids" Then

            MkDir Filepath

    End If

    FileName = Mid(swDraw.GetPathName, InStrRev(swDraw.GetPathName, "\") + 1)

    FileName = Left(FileName, InStrRev(FileName, ".") - 1)

    swDraw.SaveAs (Filepath + FileName + "" + resolvedValOut + ".PDF") 'Change the custom property text here

    End Sub