how to use a external css file

[autopost]

hi all

i want help from any buddy who can? as early as possible.
i have made a external css file and now its Font , Div tags css is not showing its working.although its other css ags are working proterly like input,select etc.
can reply personely at : <!-- e --><a href="mailto:[email protected]">[email protected]</a><!-- e -->
thanks in advance.
i am using a syntex to use this font,div style ..........

eg.
FONT.<identifiername> {attributes:value;..............}
DIV.<identifiername> {attributes:value;..............}
FONT.formheader_font{


............
.........
}

or

font.formheader{
...........
.............

}
or

input,font.formheader{
..........

.........
}

same with div tag.font is depreciated and will probably not work correctly in a css.
If the div class is between the 2 font rules it is more than likely being ignored.
Validate (<!-- m --><a class="postlink" href="http://jigsaw.w3.org/css-validator/">http://jigsaw.w3.org/css-validator/</a><!-- m -->) your css.