simple calculator that shows the different between 2 numbers in C# : <p>first of all sorry for my broken language. i would like to create a calculator that shows the different between 2 numbers in C#
i tried to make it but i always end up with adding the textbox 1 to the textbox 2 and displaying the total in text box 3, which i don't want to do
please see the GUI , it's simple
i also would like to make the number in green color if the different is positive and red if the different is negative. see the picture 
thanks!
<a href="https://i.stack.imgur.com/Ziw26.png" rel="nofollow noreferrer">simple gui</a></p>
