Sales Management System Project using c# in visual studio $2015$

Requirements

$1.$ User Authentication:

$$ The system should prompt the user to enter a username and password to log in$.$

$2.$ Data Entry Sections:

$$ After logging in$,$ the system should prompt the user to enter information divided into

three sections:

a$.$ Invoice Information:

$$ Customer Type $($Cash$,$ External, Internal$)$

$$ Invoice Number

$$ Invoice Date

$$ Seller Name

b$.$ Customer Information:

$$ Customer Name

$$ Phone

$$ Address

c$.$ Product Information:

$$ Barcode

$$ Product Name

$$ Price

$$ Quantity $($maximum $5)$

$$ Discount Rate:

o Cash customers: $15\%$

o External customers: $10\%$

o Internal customers: $12\%$

o Total: calculated automatically as $($quantity $*$ price$)-$ discount

$3.$ Field Requirements:

o All fields are required.

$4.$ Functionalities:

o Allow the user to save the invoice

o Print the invoice

o Delete the invoice

o Delete all available invoices

o Print the total sum $($Total sum $=$ sum of all product totals$)$

Implementation Steps

User Authentication Module:

o Create a login form with fields for username and password.

Data Entry Form:

o Create a form with sections for Invoice Information, Customer Information, and

Product Information.

o Ensure all fields are marked as required.

o Add validation rules, especially for numeric fields and maximum quantity.

Invoice Calculation:

o Implement logic to calculate the total amount based on quantity, price, and discount

rate.

o Display the calculated total automatically.

Invoice Management:

o Provide options to save, print, and delete individual invoices.

o Implement functionality to delete all invoices.

o Provide a summary option to print the total sum of all invoices.