TMNR on "Add a custom font using @font-face"

Hi,

How do i add a custom font using @font-face? I've tried following this tutorial: http://www.evolutionarydesigns.net/blog/2012/04/02/how-to-add-custom-fonts-to-wordpress/ but for some reason the font i try to change is being set to default Times New Roman. Here's what i've added to the top of style.css:

@font-face {
font-family: FuturaLTNormal;
src: FuturaLTNormal.ttf;
}
a {font-family: FuturaLTNormal;}

The font FuturaLTNormal.ttf is in the same directory as style.css.

Thanks