Form of calculation of car rental cost

The HTML form. Validation of the form and logic is described using JavaScript. A permanent customer can find himself by name through the search line. The database of permanent customers is stored in JSON format. When choosing from a permanent customer base, all user fields of forms are filled automatically. Below we select the type of the car, additional options (if necessary) and indicate the duration of the rental (in days). After pressing the "Calculate" button, the cost of the rental is calculated.