PayPal With drop-down box

[Camel_Booter]

I want to make the donation botton with a drop-down box with the $$ amout...

This is the PayPal HTML:

<form action="https://www.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="bn" value="AMPPFPWZ.200">
<input type="hidden" name="cmd" value="_xclick">
<input type="hidden" name="business" value="camel_booter@yahoo.com" >
<input type="hidden" name="item_name" value="">
<input type="hidden" name="item_number" value="">
<input type="hidden" name="amount" value="5">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="undefined_quantity" value="1">
<input type="hidden" name="image_url" value="">
<input type="image" src="http://images.paypal.com/images/x-click-but04.gif" border="0" name="submit">
</form>


This is the $ amout in the paypal Form:

<input type="hidden" name="amount" value="5">

But I want the value to have a drop-down box to select different amounts like this:

select size="1" name="D1">
<option>&lt; Amount &gt;</option>
<option value="1">$1</option>
<option value="2">$2</option>
<option value="3">$3</option>
<option value="4">$4</option>

How do i do this?? Thanks to all that help!!!

[Camel_Booter]

<form method="POST" action="https://www.paypal.com/cgi-bin/webscr">
<input type="hidden" name="bn" value="AMPPFPWZ.200">
<input type="hidden" name="cmd" value="_xclick">
<input type="hidden" name="business" value="Youremail.email.com">
<input type="hidden" name="item_name" value="Donation">
<input type="hidden" name="item_number" value>
<input type="hidden" name="amount" value>
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="image_url" value>
<p align="center"><select name="amount" size="1">
<option selected value="0"></option>
<option selected value="0">Amount of Credits</option>
<option value="1">$1.00</option>
<option value="2">$2.00</option>
<option value="3">$3.00</option>
<option value="4">$4.00</option>
<option value="5">$5.00</option>
</select> </p>
<p align="center">
<input type="image" src="http://images.paypal.com/images/x-click-but04.gif" border="0" name="I1" width="62" height="31"></p>
<p align="center">
</p>
</form>