[Solved] Where do I put this CSS code?

Hello Everybody,
I'm trying out some code that highlights the search keywords in the returned document. I'm not up on my CSS and not sure where to put this code (below). I made a simple page of text to test this on and there is no formatting. I don't have a css section.

Where do I put this code ? I'm using DreamweaverMX.

Thank you
NL

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<!-- Paste this code into the CSS section of your HTML document -->

.searchword {
background-color: #FFF79F;
}

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end