If you have a number of membership options in PHP-SecureArea, these can be all displayed and selected from one drop down list.
For example :
<form action="/phpsecurearea/ipn/process.php" method="post">
<select name="item_number">
<option value="Memb01">1 month membership (£10.00)</option>
<option value="Memb03">3 month membership (£20.0)</option>
<option value="Memb06">6 month membership (£35.00)</option>
<option value="Memb12">12 month membership (£60.00)</option>
</select>
<input type="image" src="/phpsecurearea/images/btn/x-click-butcc-subscribe.gif" border="0" name="submit" alt="" title="Make payments with PayPal - it's fast, free and secure!" />
</form>
You first have to create separate product items in PHPSecureArea, for 1, 3, 6 and 12 months.
Entering them into the drop down list will provide the customer with an easy way to select instead of creating a button for each product.