CSS for Custom Headlines, etc

I have tried and tried to get my Font Face fonts to work and they just continue to default to Helvetica.

Our site is here: http://gotham.commuterind.com/

Can you tell me what the CSS code is to implement my fonts into the Headers, Subheaders, and general content?

I’ve tried all of the following WITHOUT ANY LUCK:

body {
font-family: ‘AvianoSansLight’;
font-weight: normal;
}

.main_title h1, h2, h3, h4 {
font-family: ‘AvianoSansLight’ !important;
font-weight: normal !important;
}

.avia-main-title h1, h2 {
font-family: ‘AvianoSansLight’ !important;
font-weight: normal !important;
}

h1.av-special-heading-tag {
font-family: ‘AvianoSansLight’ !important;
}

h3.av-special-heading-tag {
font-family: ‘AvianoSansLight’ !important;
}

h4.av-special-heading-tag {
font-family: ‘AvianoSansLight’ !important;
}

Please help!

-Glen