gistfile1.txt

<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>
<script src="https://checkout.stripe.com/checkout.js"></script>

<button id="customButton">Purchase</button>

<label><input type="radio" name="amount" value="2000" data-description="DESCRIBE $20 PRODUCT HERE">$20</label>
<label><input type="radio" name="amount" value="5000" data-description="DESCRIBE $50 PRODUCT HERE">$50</label>
<label><input type="radio" name="amount" value="10000" data-description="DESCRIBE $100 PRODUCT HERE">$100</label>

<script>
  var handler = StripeCheckout.configure({
    key: 'pk_test_ahu1YHgH8D5BMaKmm3IX3aav',
    image: 'YOUR_LOGO_HERE.JPG',
    token: function(token, args) {
      // Use the token to create the charge with a server-side script.
    }
  });

  document.getElementById('customButton').addEventListener('click', function(e) {
  
    // cache the selected radio button here
    var $selected = $('input[name=amount]:checked') 
  
    // Open Checkout with further options
    handler.open({
      name: 'YOUR STORE NAME HERE',
      description: $selected.data('description'),
      amount: $selected.val()
    });
    e.preventDefault();
  });
</script>