I see a couple of problems.
For one thing, is the script on a different server or are you just calling it by it's ip address in one place and the domain name in another? You have the action tag pointing to:
but the domain that the form page and the thank you page are on is:
If the script is on a different server, then you must specify the entire url for the thank you page, such as:
<input type="hidden" name="redir" value="
Problem #2:
Here's the code that you have for your thank you page:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><HTML><HEAD><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="Generator" CONTENT="NetObjects Fusion MX for Windows"><TITLE>Thank You</TITLE><html>
<head>
<title>Disappearing Thank You Page</title>
</head>
<body onLoad="self.close()">
</body>
</html><BASE TARGET="_parent"><LINK REL=STYLESHEET TYPE="text/css" HREF="./style.css"><LINK REL=STYLESHEET TYPE="text/css" HREF="./site.css"><STYLE></STYLE></HEAD><BODY NOF="(MB=(ZeroMargins, 0, 41, 0, 2), L=(ThankYouLayout, 770, 420))" STYLE="background-color: rgb(255,255,255); background-image: none;" TOPMARGIN=0 LEFTMARGIN=0 MARGINWIDTH=0 MARGINHEIGHT=0></BODY></HTML>
Not only is the code incorrect (more than one html tag, etc.), but you don't need all that for a blank page. Just delete all of that and replace it with what I posted earlier:
<html>
<head>
<title>Disappearing Thank You Page</title>
</head>
<body onLoad="self.close()">
</body>
</html>
By the way, why are these pages in frames?
. . and there's no php involved in any of this.
