why not make it a Donation Button instead
If you want to create a PayPal donation button on a website then follow this instructions
Step-by-step to create PayPal donation button
1. Login your PayPal account, goto “Merchant Tools”. Scroll down to “PayPal Website Payments Standard“.
2. There is a link named “Donations“. Click it to open donation button setup page.
3. There looks many fields need to fill in… Don’t worry, you can ignore those “(optional)” field.
4. If you want to specific a donation amount, fill in the “Donation Amount:“.
Note: Once specified the amount, the donator cannot donate more than or less than the specified valune.
5. Under “Choose a donation button to put on your website (optional)“, you can choose a donation button or use your own image.
6. For “Security Settings“, I recommend to select “Yes” to encrypt your payment button. It will protect your paypal email address.
7. Then, click the “Create Button Now” button at the bottom of the page to create your PayPal donation button.
8. You will given a HTML code for the donation button. Copy it and paste into your website.