Type mismatch: 'thedate'

Jeg får en fejl på linje 22 som er:
if datediff("d",thedate,Date) <> 0 then

Fejlen er:
Microsoft VBScript runtime error '800a000d'

Type mismatch: 'thedate'

/LM/w3svc/8837/ROOT/global.asa, line 22


min kode:
<script language="VBScript" Runat="server">
sub application_onstart
Dim objFSO
Dim objStream
Dim intLine
Dim thedate

Const ForReading = 1
Const ForWriting = 2

Set objFSO = Server.CreateObject("Scripting.FileSystemObject")
If objFSO.FileExists(Server.MapPath("update.txt")) Then
    Set objStream = objFSO.OpenTextFile(Server.MapPath("update.txt"), ForReading)
    intLine = objStream.ReadLine
    objStream.Close
    Set objStream = Nothing
Else
    'Gør ikke noget
End If

thedate = trim(replace(intLine,"RunDate =",""))
if datediff("d",thedate,Date) <> 0 then
  'Gør ikke noget
else
  response.redirect("test.asp")
end if
Set objFSO = Nothing
end sub
</script>