If txtCustomer.Text.Length = 0 AndAlso
txtHours.Text.Length < 0 AndAlso txtParts.Text.Length = 0 Then
txtHours.Text.Length will never be LESS THAN 0.
11. Convert the customer name variable to upper case before displaying it in the listbox.
In VB.NET, you can use ToUpper, UCase or StrConv
14. Be sure to use currency format where appropriate.
FormatCurrency.

When you post, it is a good idea to put CODE tags round your code to make it much easier to read. Also, don't say, " I AM GETTING AN ERROR". You need to specify what the error is and on which line it is occurring. Failure to provide a clear description of your needs leads to confusion and very often incorrect advice.