Pay pal form post Modify payment amount while submitting - security

Question

I have a used Paypal Html form post for my eCommerce site.
<form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post" target='_new' id='paypalForm'>
<input name="currency_code" type="hidden" value="<?php echo "EUR"; ?>" />
<input name="shipping" type="hidden" value="<?php echo "00.00"; ?>" />
<input name="tax" type="hidden" value="00.20" />
<input name="return" type="hidden" value="<?php echo "http://www.web.com/login.php"; ?>" />
<input name="cancel_return" type="hidden" value="<?php echo "http://www.web.com/cancel.php"; ?>" />
<input name="notify_url" type="hidden" value="<?php echo "http://www.web.com/ipn.php"; ?>" />
<input name="cmd" type="hidden" value="_xclick" />
<input name="business" type="hidden" value="<?php echo "XXXXXXXXXXX"; ?>" />
<input name="item_name" type="hidden" value="camp" />
<input name="no_note" type="hidden" value="1" />
<input name="lc" type="hidden" value="EN" />
<input name="bn" type="hidden" value="PP-BuyNowBF" />
<input name="amount" type="hidden" value="100" />
</form>
And the Javascript
var form = $("form");
form.submit();
I have found that by triggering a form submit function in console, I am able to update the amount that is passed to the Paypal payment process. So, Anyone can do the same right. Is there a secure way to do the payment process using form post in Paypal

Answer 1

Yes, instead of using plain text button (like the one used in your example), use hosted button.
When you use hosted button all the information is store on PayPal side. You just need to pass hosted button id in form.
See if the following link helps:
https://developer.paypal.com/docs/classic/paypal-payments-standard/integration-guide/buy_now_step_1/