This in-depth assignment is for those who like a challenge. There will be less explanation and you have to have a bit more perseverance. If you succeed in completing this in-depth challenge then you'll have gained significant more knowledge of writing C# source code!

Sometimes it'll be better to just complete the standard assignments first and then the in-depth assignments. Choose your own path like we normally do in our education. A collection of Frequently Asked Questions.

Vehicles

The customers (Paaspop) wish is to apply different prices for different vehicles. For example a caravan is more expensive to have on the terrain than a tent (do mind: a caravan is a car with a caravan). Paaspop suggests these prices per vehicle:

caravan	€120
camper	€100
car	€60
motorcycle	€40

Because we've made it in a way that other vehicles disappear when an employee clicks a vehicle, it's possible to use the source code below to check if a camper is selected. In this example the camper is shown in PictureBox2:

if (pictureBox2.Visible)
{
  MessageBox.Show("Totaalprijs: " + (100 + numericUpDown1.Value * 20));
}

This piece of source code replaces the current source code below the last Button. If you test your program (pres Start) you'll notice that you'll see a total price only when a camper (PictureBox2) is selected. Now copy this piece of code a few times so for each vehicle (PictureBox#) a total price is calculated. Make sure the right amount is used and check the "if" statement for the right PictureBox usage.

Further elaboration

Make sure it works for all vehicles. You'll have as many "if statements" as vehicles because each "if statement" has its own MessagBox and price calculation.
For the employee its difficult to handle another customer because all vehicles are "gone" once he has calculated a price. The employee has to start the program again each time and that's not efficient. Do add a "Reset" button for the employee so he can make all vehicles visible again. Do search the internet for how to make a PicureBox visible again.