I am taking my first class (online) in Visual Basic and we are using VB 2010. The assignment is to create a football calculator(see attached). I have attached the instructions that the teacher gave us and I think that I created the user interface okay but I don't understand about how to declare variables and how to calculate. I also don't understand what a LostFocus event is. I am also not sure if I should use regular text boxes or masked text boxes. Any guidance would be much appreciated as I want to learn this, it's just the book doesn't seem to explain this very well and I have searched for help on calculating but it seems the examples are showing as if you have a calculate button.