link rel="help" href="http://www.w3.org/TR/CSS21/box.html#propdef-border-top-width" />
        <link rel="help" href="http://www.w3.org/TR/CSS21/box.html#border-width-properties" />
        <link rel="match" href="border-top-width-012-ref.xht" />

        <meta name="flags" content="invalid" />
        <meta name="assert" content="The 'border-top-width' property does not support a negative length value in 'em' units and resets to the initial value." />
        <style type="text/css">
            span
      