CSS hover button code

So I found this site http://www.myneatsite.com/blog/2006-06-30/creating-pure-css-3d-hover-buttons-text-only-no-images/

and pasted that css and html code they show and put it where they told me, but it makes every button on the forum this way....i just want the header's buttons to be hover...any idea how i can achieve this this..

i put this code

a {
text-decoration:none;
font-weight:bold;
border:3px solid;
padding:2px;
border-color:#6cf #2af #2af #6cf;
background:#9df;
}
a:hover {
border-color: #2af #6cf #6cf #2af;
}

in the CSS

and this

<a href="#">Submit</a>

in the HTML

Thanks!

someone on here told me it was impossible to do this, but i think they were wrong

come on, no one wants to help me out