Please help with Chained Select Menu in php file

[harmpie_]

1) Script Title:

2) Script URL (on DD): http://www.macproductions.nl/mail_form.rar

3) Describe problem:

Hello,

My name is Harm and I’m from the Netherlands, I have a problem with my php mailing form.
It’s a Chained Select Menu the same you can find on DynamivDrive.com
In the HTML file the 3 fields where in you can choose a car, model and type, it works butt when I copy it to the php file it stops working.
Can you help me solve this problem???
(if a'm posting this wrong, let me know. i'm new here...)

Best regards,

Harm Harmsen