CS 230 Spring 2007          Assignment 7 – Sub Procedures and Function Procedures                                       100 points

Assigned: 03/14/2007

Due: 03/21/2007 at the start of class

Pre-Lab (Do Before Lab):  Bring materials – a way to save a copy for you and a copy to turn in. Plan out tasks, objects, and events needed for program. Write pseudocode for the main button and for functions / independent sub procedures

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Main Assignment:

Casinos are coming to the Philadelphia area!  Imagine that you are writing the beginnings of a very basic program for a dice game.  This time the user is allowed to win!  The first time playing, the user will enter into a textbox how many “points” they have to start. They will also enter (each time they want to play) a guess for the total for all rolled dice. When a “Roll” button is Clicked, the program should (do this in a function!) generate a random number of rolls between 10 and 20, and roll a die that many times, keeping track of the total.  If the player’s guess is below (or equal) the total of the rolled dice, they win the number of points that they guessed.  If the players guess is greater than the total of the rolled dice, they lose the number of points that they guessed.  After the roll has been completed, display in labels or read-only textboxes the number of rolls, and the total, and the user’s result (how much they won or lost), along with updating the users current balance of points.   

· Provide capabilities to play, clear (the inputs and outputs except the user’s balance), reset (to start over again – clear the balance too and make it no longer read-only), and to exit.

Hand in:

• Floppy disk  or CD-R with an entire folder containing all files related to the project (or e-mail with zipped attachment containing all files related to the project). Please set the name of the project to something other than the default name (WindowsApplication1, …). It is helpful if you use a name that identifies you as well as the assignment (e.g. yourlastname assignment 7). Use Windows to copy the whole folder, instead of trying to “Save As”.
• Print out of your code.  

Task Details:

· In this task, we mainly only get one of the benefits of procedures and functions (dividing up into manageable tasks). Most procedures or functions you would write will only be called from one place in your code. However, you must write some procedures and functions for this assignment (and use them!)

o The rolling of dice must be handled by a function

o Determining if the user wins or loses (and how much) should be handled by a function

o If we have covered validating inputs using a function on Wed, then you need to do that (otherwise it is optional)

o Use a independent sub procedure to clear textboxes for clear and reset capabilities

• Define numbers (especially those that could change sometime in the futures) as named constants
• After the user plays the first time, set the textbox for their balance to be read only.
• We’re no longer going to assume that the clerk enters valid and reasonable values.  Ensure that the user’s guess is positive and numeric. Ensure that the user’s balance of points is positive and less than a million. Don’t try to calculate anything if bad data has been entered (display a message).  For simplification don’t worry if balance is negative whether it is a user error or if the user has just gone broke; the same message can be used.
• MAKE SURE YOUR PROGRAM WORKS! (i.e. gets the correct answers).  It doesn’t have to just run, it needs to run correctly!  It should run on any inputs (We are now branching – so the program must be tested on more inputs to ensure that all paths through the program code work!). For instance, does your program still do the right thing no matter how many of the inputs are invalid?   Think up some different examples to test the program on. 

Miscellaneous

• You must turn on Option Explicit and Option Strict.
• Put YOUR NAME, e-mail address, date, and purpose of the program in comments at the beginning of the program. The purpose should be what the program is supposed to do, not the learning goals. Comments are indicated with a single quote (everything after the single quote is only for humans)
• You MUST include comments that explain your program in order to get full credit.
• Remember to use meaningful variable names
• Remember to indent to show the structure of the program (VB usually does this correctly).
• Name all textboxes and buttons meaningfully, and use conventions for starting their names.
• Make textboxes that user should never enter a value in (results / outputs) “Read Only”.
• Put your name on the form as a Label or as part of the form title.
• Try to use good user interface design. Make clear what user needs to do and what the answers mean. Make error messages as clear and helpful as possible!