Visual Basic Function Procedure - vb6

Question

I need help with the following H.W. problem. I have done everything except the instructions I numbered. Please help!
A furniture manufacturer makes two types of furniture—chairs and sofas.
The cost per chair is $350, the cost per sofa is $925, and the sales tax rate is 5%.
Write a Visual Basic program to create an invoice form for an order.
After the data on the left side of the form are entered, the user can display an invoice in a list box by pressing the Process Order button.
The user can click on the Clear Order Form button to clear all text boxes and the list box, and can click on the Quit button to exit the program.
The invoice number consists of the capitalized first two letters of the customer’s last name, followed by the last four digits of the zip code.
The customer name is input with the last name first, followed by a comma, a space, and the first name. However, the name is displayed in the invoice in the proper order.
The generation of the invoice number and the reordering of the first and last names should be carried out by Function procedures.

Answer 1

Seeing as this is homework and you haven't provided any code to show what effort you have made on your own, I'm not going to provide any specific answers, but hopefully I will try to point you in the right direction.
Your first 2 numbered items look to be variations on the same theme... string manipulation. Assuming you have the customer's address information from the order form, you just need to write 2 separate function to take the parts of the name and address, take the data you need and return the value (which covers your 3rd item).
To get parts of the name and address to generate the invoice number, you need to think about using the Left() and Right() functions.
Something like:
Dim first as String, last as String, word as String
word = "Foo"
first = Left(word, 1)
last = Right(word, 1)
Debug.Print(first) 'prints "F"
Debug.Print(last) 'prints "o"
Once you get the parts you need, then you just need to worry about joining the parts together in the order you want. The concatenation operator for strings is &. So using the above example, it would go something like:
Dim concat as String
concat = first & last
Debug.Print(concat) 'prints "Fo"
Your final item, using a Function procedure to generate the desired values, is very easily google-able (is that even a word). The syntax is very simple, so here's a quick example of a common function that is not built into VB6:
Private Function IsOdd(value as Integer) As Boolean
If (value Mod 2) = 0 Then 'determines of value is an odd or even by checking
' if the value divided by 2 has a remainder or not
' (aka Mod operator)
IsOdd = False ' if remainder is 0, set IsOdd to False
Else
IsOdd = True ' otherwise set IsOdd to True
End If
End Function
Hopefully this gets you going in the right direction.