Convert distances TO and FROM (in. & ft.) using 2 listboxes.

Question

I am currently trying to do a practice program from the "Starting out with Visual C# 2012" textbook and I completed programming problems 1-4 but, I am stuck on number 5 "Distance Converter".  The problem states that I have to create a program that allows the user to convert distances TO and From: Inches, Feet and Yards using 2 listboxes.

 

ex.

 

the user inputs a number and depending on which items are selected from each of the listboxes, will determine the output.

 

Listbox1 has Inches, Feet, Yards

Listbox2 has Inches, Feet, Yards 

 

*if the user inputs 50 and selects "Inches" from Listbox1 and selects "Feet" from Listbox2 then the output will show what 50 is, converted from inches to feet, etc.