The conversion of the entered amount in rubles (taking into account the exchange rate) in dollars.
Settings:
- .main-form - class of the form element that will send data (1 form of that class in document)
- input - class of input elements contained in .main-form (some elements of such class but only on main form)
- div - new element that will be added to 'main form' for displaying message with result of form submit
- url - link to POST (in our example we are using server.php in same directory as index.html)
- message - object that contains a set of messages for user.