How to get Visual Studio 2010 to highlight instances of a variable

Question

I\'m new using vs2010 I\'ve read that when you click on a variable its suppose to highlight all the instances of that variable in that file and highlight red or show an error as

Answer 1

In visual Studio 2012, Tools -> Options -> Environment -> Fonts and Colors -> [Text Editor] [Display Itemns] -> Highlighted References -> Item background: Choose the color you want.