Our initial markup

Let's begin with a very simple markup, shown here in the Source view:

Figure 6.1.1: The initial simple markup for this chapter

If we switch over to the Design view, all we have is a button that says Show Balance, and under it a Label control where the balance can actually be displayed, as shown in the following screenshot:

Figure 6.1.2: The initial interface in the Design view

Creating a class

Now, double-click on Show Balance. Here, we will create a class that represents bank accounts. Start by deleting comment 4, which is not suitable for our purposes, and then enter the following under using system:

class BankAccount

Here, class is a keyword, so it's blue of course, and BankAccount is an identifier...