PHP Newbie looking for simple file attachment script

I'm new to PHP, and wrote the following page to submit my first form using PHP! It works great, but now I want to add the ability for the user to attach a file that will come through in the email, but am at a loss. I've found several scripts that let you add files, but they're all in functions with all the rest of the code, which I don't need, and am at a loss. Also, I'm using php 4.3.2, and $file is the variable that is currently the file path.

Any help would be greatly appreciated. Here's the php code I'm using for the formmail.

TIA

<?php
$name=$_POST['name'];
$name=$_POST['name'];
$streetaddress=$_POST['streetaddress'];
$city=$_POST['city'];
$state=$_POST['state'];
$zip=$_POST['zip'];
$phone_number=$_POST['phone_number'];
$cell_number=$_POST['cell_number'];
$email=$_POST['email'];
$school=$_POST['school'];
$major=$_POST['major'];
$availability=$_POST['availability'];
$department=$_POST['department'];
$comments=$_POST['comments'];
$file=$_POST['file'];

if ((!$name ) or (!$email)) {

echo "Please enter a Name and an Email address for Contact purposes.
Thank You";
echo "<p>";
echo "Please use the 'Back' button to continue.";
echo "</p>";
echo "<a href='interns3.php' onclick='self.history.back();'>Back</a>";
exit;
}
$message="Name: $name\n\n"."Address: $streetaddress\n\n"."City: $city\n\n"."State: $state\n\n"."Zip: $zip\n\n"."Phone: $phone_number\n\n"."Cell Phone: $cell_number\n\n"."Email: $email\n\n"."School: $school\n\n"."Major: $major\n\n"."Availability: $availability\n\n"."Department: $department\n\n"."Comments: $comments\n\n".$text;
$subject="Internship Contact Form";
mail("myemail@myemail.com","$subject","$message","From:Form.$email\r\nReply-to:$email", "$file");
echo "<p>Thank you for completing our contact form. Your details have been forwarded.</p>";
echo "<p>";
echo $text;
echo "</p><a href=home.php'><b>Return to Home Page</b></a>";
?>