what’s wrong with this code..?

I use this code for my site login script (it's basically -borg-'s code slightly modified)......... The problem is that i got a JavaScript pop up at the end of the code (text in red) and all the code is getting executed but those lines so i don't get no pop up when the password is incorrect. Any ideas why this is happening? here's the code:

'If a username has been entered check that the password is correct
If NOT strUsername = "" Then

 'Read the various forums from the database
 'Initalise the strSQL variable with an SQL statement to query the database
 strSQL = "SELECT tblAuthor.Password, tblAuthor.Salt, tblAuthor.Author_ID, tblAuthor.User_code "
 strSQL = strSQL & "FROM tblAuthor "
 strSQL = strSQL & "WHERE tblAuthor.Username = '" & strUsername & "';"

 'Query the database
 rsCommon.Open strSQL, adoCon

 'If the query has returned a value to the recordset then check the password is correct

 If NOT rsCommon.EOF Then

  'Encrypt password so we can check it against the encypted password in the database
  'Read in the salt
  strPassword = strPassword & rsCommon("Salt")

  'Encrypt the entered password
  strPassword = HashEncode(strPassword)

  'Check the encrypted password is correct, if it is get the user ID and set a cookie

  If strPassword = rsCommon("Password") Then

   'Read in the users ID number and whether they want to be automactically logged in when they return to the forum
   lngUserID = CLng(rsCommon("Author_ID"))
   strUserCode = rsCommon("User_code")

   'Write a cookie with the User ID number so the user logged in throughout the forum
   'Write the cookie with the name Forum containing the value UserID number
   Response.Cookies("Forum")("UID") = strUserCode
   If CBool(Request.Form("ActiveUsers")) = False Then
    Response.Cookies("Forum")("Hide") = True
   Else
    Response.Cookies("Forum")("Hide") = False
   End If

   'If the user has selected to be remebered when they next login then set the expiry date for the cookie for 1 year
   If blnAutoLogin = True Then

    'Set the expiry date for 1 year
    'If no expiry date is set the cookie is deleted from the users system 20 minutes after they leave the forum
    Response.Cookies("Forum").Expires = DateAdd("yyyy", 1, Now())
   End If

   'Reset Server Objects
   rsCommon.Close
   Set rsCommon = Nothing
   adoCon.Close
   Set adoCon = Nothing
   Response.Redirect strNewRedir

         End If

 End If

'Popup alert if username or password is invalid
Response.Write("<script  language=""JavaScript"">")
Response.Write("alert('Invalid Username And/Or Password');")
Response.Write("</script>")

End If

I tried that before and it didn't work neither

right after that code i got this code:

'Reset Server Objects
Set rsCommon = Nothing
adoCon.Close
Set adoCon = Nothing

If blnGuest Then

'Redirect to the page where this script was loaded from
If strNewRedir = "" Then strNewRedir = Request.ServerVariables("URL")
If strNewRedir <> Request.ServerVariables("URL") Then Response.Redirect strNewRedir

That way after the login or log off the user is redirected to the same page they were at (i got this script included in all pages on my site)...so i can't really look at the source cuz i get redirected right away...

If i comment out the later code it will display the javascript pop up but then the script wouldn't work correctly, so the actual problem i guess is that the redirect is being executed before the javascript.........how can that happen if the javascript is first..???

I've tried everything,

i made a new file with just the javascript pop up and a <% Response.Redirect %> line and change my login script to redirect to that page but it'll also execute the asp line and not the javascript, i tried making an .htm file with just the javascript and include it using include file and it didn't work neither, it executes the Response.Redirect commands but it doesn't spit out any javascript or html to the browser...

'Popup alert if username or password is invalid
Response.Write("<script  language=""JavaScript"">")
Response.Write("alert('Invalid Username And/Or Password');")

Response.Write("window.location=""page.asp"";")
Response.Write("</script>")

Uses javascript to redirect the user...