title: form temparing Payment
body: <p>I have a payment form which calculates payment on the selection of some items on the page and final amount to pay goes to payment gateway from an hidden field in the form. If user changes the amount by inspecting DOM, my form submits the changes amount and same goes to payment gateway. How can I secure my form for this temparing.</p>
  
  <p>Thanks 
  Umar</p>