Question

Option Strict On

Public Class Form1
'Project:  
'Author: 
'Date created: 9/8/2011
'Program Description: Program.

Private Sub btnData_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnData.Click

    '0. Declare variables
    Dim customerName As String
    Dim phoneNum As String
    Dim ticketPrice As Double
    Dim firstName, lastName As String
    Dim position As Integer
    Dim amountPaid As Double
    Dim areCode As String

    '1. Collect data: Customer name, phone number, ticket amount, and cash paid (use an input box)
    'get customer name from a textbox
    customerName = CStr(txtCustName.Text)

    'get phone number from a masked textbox
    phoneNum = mskPhone.Text

    'get ticket price from a textbox
    ticketPrice = CDbl(Val(txtTicket.Text))

    'get cash paid from a input box
    amountPaid = CDbl(Val(InputBox("Cash paid", "Lab2", "20")))

    '2. Rearrange name (Last, First)
    position = customerName.IndexOf(" ")
    firstName = customerName.Substring(0, position)
    lastName = customerName.Substring(position + 1)

    '3. Extract area code
    areCode = phoneNum.Substring(1, 3)

    '4. Calculate the change

    '5. Print data. Use the working version as a reference for your output.
    'print customer name

    lstDisplay.Items.Add("Customer Name: " & lastName & ", " & firstName)

End Sub

End Class

Answer 1

The error is fairly self-explanatory. txtCustName is used, but not defined, in Form1. You’ll need to define the variable before you can use it, in a syntax like:

Dim txtCustName As Textbox

Does txtCustName (which I’m assuming is meant to be a Textbox) exist on your form? If not, create it.