Bug 163013 Missing Document Type Definition (DTD) in the DOCTYPE declaration of the HTML output
engine/org.eclipse.birt.report.engine.emitter.html/src/org/eclipse/birt/report/engine/emitter/html/AttributeBuilder.java
buildProperty( content, HTMLTags.ATTR_BACKGROUND_ATTACHEMNT, style
					.getBackgroundAttachment( ) );
			String x = style.getBackgroundPositionX( );
			String y = style.getBackgroundPositionY( );
			if ( x != null || y != null )
			{
				if ( x == null )
				{
					x = "0pt";
				}
				if ( y == null )
				{
					y = "0pt";
				}
				addPropName( content, HTMLTags.ATTR_BACKGROUND_POSITION );
				addPropValue( content, x );
				addPropValue( content, y );
				content.append( ';' );
			}
		}
	}
	/**
	 * Build the Box style string.
	 * 
	 * @param content
	 *            The <code>StringBuffer</code> to which the result is output.
	 * @param style
	 *            The style object.
	 */
	private static void buildBox( StringBuffer content, IStyle style )