How to use webfont with @font-face

I want to change the font in my application to a custom font but the following code is not working:

@font-face 
{
font-family: "ArnoProBold"; 
src: url("resources/fonts/ArnoProBold.ttf");
}
@font-face 
{
 font-family: "ArnoProCaption"; 
 src: url("resources/fonts/ArnoProCaption.ttf");
}
@font-face 
{
 font-family: "Arn";
 src: url("resources/fonts/ArnoProLightDisplay.ttf");
}