This process demonstrates the use of dynamic subprocesses in a loop. Given the mode ('rent now' or 'book') chosen by the user, a different sub-process is called in the loop task. It also shows how to manipulate a list of business objects (Bike) using getters and setters. With this feature, you can use a single business object in one or several forms instead of having to create a variable for each form field. In the step "choose dates" you can also see how to update a data field (using HTML attributes) when the value of another data field changes.