What you have in mind is not a feature however, there are work arounds. Trying to modify a Donation Button has it limits when it comes to collecting additional information. As you can't use the option variables with the actual Donation command, the trick is to use a Buy Now command and the Donation Graphics. Since you can't be sure that the donor will provide the additional info you want, you can add a script to the code to make the text input fields required. Note, because this method does not use the actual command for Donations, it works similar to Buy Now item button code. You won't see the "Purpose" or "Donation Amount" headers on the PayPal Checkout Screens. If you take advantage of the "item_name" variable value - you can include what the Donation is for, example: "Widget Donation Project". You still pay the standard transaction processing fees regardless of the type of item button you use so that's not an issue. For learning purposes, check out the example code below - you can try it by replacing the "business" value with your PayPal Email Address or your Merchant Account ID.
<!doctype html>
<html lang="en">
<head>
<title>Button Example</title>
<!-- START META TAG SECTION -->
<meta name="Description" content="">
<meta name="KeyWords" content="">
<meta charset="UTF-8">
<!-- END META TAG SECTION -->
<!-- Start of Script -->
<script type="text/javascript">
<!--
function CheckForm(obj1) {
if (obj1.amount.value == ""){
alert ("You must fill in a value for the Amount!");
return false;
}
if (obj1.os0.value == ""){
alert ("You must fill in a value for Option 1!");
return false;
}
else if (obj1.os1.value == ""){
alert ("You must fill in a value for Option 2!");
return false;
}
else if (obj1.os2.value == ""){
alert ("You must fill in a value for Option 3!");
return false;
}
else if (obj1.os3.value == ""){
alert ("You must fill in a value for Option 4!");
return false;
}
return true;
}
//-->
</script>
<!-- End of Script -->
</head>
<body>
<!-- Start of Button Form -->
Widget Donation Project
<br><br>
<form name="paypal" target="paypal" action="https://www.paypal.com/cgi-bin/webscr" method="post" onsubmit="return CheckForm(this);">
<input type="hidden" name="cmd" value="_xclick">
<!-- Replace "business" value with your PayPal Email Address or your Merchant Account ID -->
<input type="hidden" name="business" value="your email addres">
<input type="hidden" name="item_name" value="Widget Donation Project">
<input type="hidden" name="item_number" value="WDP-10001">
<input type="hidden" name="tax" value="0">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="lc" value="US">
<input type="hidden" name="bn" value="PP-DonationsBF:btn/btn_donateCC_LG.gif:NonHosted">
Please Enter Amount - Example: 5.00   
<input name="amount" type="text" id="amount" size="5">
<br><br>
<input type="hidden" name="on0" value="Option1">
Text Option 1:   <input type="text" name="os0" value="">
 (required)
<br><br>
<input type="hidden" name="on1" value="Option2">
Text Option 2:   <input type="text" name="os1" value="">
 (required)
<br><br>
<input type="hidden" name="on2" value="Option3">
Text Option 3:   <input type="text" name="os2" value="">
 (required)
<br><br>
<input type="hidden" name="on3" value="Option4">
Text Option 4:   <input type="text" name="os3" value="">
 (required)
<br><br>
<input type="image" src="https://www.paypal.com/en_US/i/btn/btn_donateCC_LG.gif" border="0" name="submit" alt="Make payments with PayPal - it's fast, free and secure!">
<img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
</form>
<!-- End of Buy Now Button Form -->
</body>
</html>
