Bug 121687 Exception throws when export data in table which inside a grid cell.
Description: Exception throws when export data in table which inside a grid cell. Steps to reproduce: 1. insert a grid. 2. insert one table to one grid cell. 3. insert another table to the other grid cell. 4. export data in two tables. Expected result: Data are exported. Actual result: Exception in: ReportEngineService.getMetaData( )
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/parser/EngineIRVisitor.java
Style.BORDER_TOP_STYLE_PROP ) );
		style.setBorderTopWidth( getElementProperty( handle,
				Style.BORDER_TOP_WIDTH_PROP ) );
		
		style
				.setMarginTop( getElementProperty( handle,
						Style.MARGIN_TOP_PROP ) );
		style
				.setMarginLeft( getElementProperty( handle,
						Style.MARGIN_LEFT_PROP ) );
		style.setMarginBottom( getElementProperty( handle,
				Style.MARGIN_BOTTOM_PROP ) );
		style.setMarginRight( getElementProperty( handle,
				Style.MARGIN_RIGHT_PROP ) );
		
		style
				.setPaddingTop( getElementProperty( handle,
						Style.PADDING_TOP_PROP ) );
		style.setPaddingLeft( getElementProperty( handle,
				Style.PADDING_LEFT_PROP ) );
		style.setPaddingBottom( getElementProperty( handle,
				Style.PADDING_BOTTOM_PROP ) );
		style.setPaddingRight( getElementProperty( handle,
				Style.PADDING_RIGHT_PROP ) );
		
		style.setNumberAlign( getElementProperty( handle,
				Style.NUMBER_ALIGN_PROP ) );
		style.setDateFormat( getElementProperty( handle,
				Style.DATE_TIME_FORMAT_PROP ) );
		style.setNumberFormat( getElementProperty( handle,