Um, I hope you don't mean like this:
<font id="heading">Blah blah</font>
This will not work in XHTML as font is no longer supported, if you want to
apply a style to an element on the page use SPAN and CLASS instead:
<style type="text/css">
.mystyle
{
font-family:Arial;
color:#00cc00;
size:140%;
}
</style>
Then in your HTML:
<span class="mystyle">This is an Arial Green font at 140% size...</span>
Remember that ID must only be used once on the page but CLASS can be used as
often as you want.
CLASS has a " . " at the start like this: .mystyle
ID has a " # " at the start like this: #mystyle
Have a look at the CSS 2 Spec at w3.org:
http://www.w3.org/TR/REC-CSS2/
RM.