create bill and print using wpf c# in visual studio

Question

hi all,

i m new to wpf well i hav created insert, update, and delete of item code, name and price.

n i hav bind the item code to the combo box too,

n now i want to create a bill in which if i select a item code in the in the combo box then consequent item name should be displayed and individual price of item should be multiplied with the quantity entered in textbox and displayed.

how can i do dat pls help

thanks & regards