Bug 148771 Bottom margin is invalid in PDF & HTML
Details: Bottom margin is invalid Step: 1.New a label. 2.New a data item. 3.New a label again. 4.Set bottom margin as -20 point Actual result: See the attach image
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/area/impl/AbstractArea.java
* 
	 * @return
	 */
	public int getAllocatedWidth( )
	{
		return width
				+ PropertyUtil.getDimensionValue( style
						.getProperty( StyleConstants.STYLE_MARGIN_LEFT ) )
				+ PropertyUtil.getDimensionValue( style
						.getProperty( StyleConstants.STYLE_MARGIN_RIGHT ) );
	}
	
	
	/**
	 * get allocated height
	 * 
	 * @return
	 */
	public int getAllocatedHeight( )
	{
		int topMarginHeight = PropertyUtil.getDimensionValue( style
				.getProperty( StyleConstants.STYLE_MARGIN_TOP ) );
		int bottomMarginHeight = PropertyUtil.getDimensionValue( style
				.getProperty( StyleConstants.STYLE_MARGIN_BOTTOM ) );
		int result = 0;
		if( topMarginHeight >= 0) result = height + topMarginHeight;
		if( bottomMarginHeight >= 0) result = result + bottomMarginHeight;
		return result;
	}
	/**