HELP!! <MvASSIGN NAME="url" VALUE="http://www.mywebsite.com/success.php"> NOT WORKIN

[imyb]

Hi, I have been using a miva script for years to process a form on my website. It's been working fine for years where it would:
1- email me the form
2- save the form info into a txt file on my server
3- re-direct the person to a page after emailing the form to thank them for signing up

I just changed my entire website to a .php website from an .html that it was for years. So, I changed my script below but for some reasons it doesn't send them to the success.php page I have. All I changed was success.html to success.php in the script. Not sure why it will not load the php page but it works if I put success.html

<MvASSIGN NAME="url" VALUE="http://www.mywebsite.com/success.php">
<MvCALL ACTION="&[url];" METHOD="GET">
<MvIF EXPR="{callobjecttype EQ 'tag' AND toupper(callobjectelement)
EQ '/HEAD'}">
<MvEVAL EXPR="<BASE HREF='&[url];'>">
</MvIF>
<MvEVAL EXPR="{callvalue}">
</MvCALL>

When I use the success.php link nothing happens. I don't see an error message, just a blank page with a very long URL on the top with all the data that was entered from the client. I don't see the URL that I am trying to send them to.

I need to load the php page since the website is not all .php

Thanks for any help!