there is a comma after formatting ('truetype') - deleted and added half-bell
format('truetype');
also remove quotes from the font family declaration in the body so that it
font-family: DINRegular, Tahoma, Geneva, sans-serif;
also, if your browser does not support .ttf here is an example of a more complete font declaration:
@font-face {
font-family: 'myfont';
src: url('myfont.eot');
src: url('myfont.eot?#iefix') format('embedded-opentype'),
url('myfont.woff2') format('woff2'),
url('myfont.woff') format('woff'),
url('myfont.ttf') format('truetype'),
url('myfont.svg#myfont') format('svg');
}