Bug 198594 XLS Emitter: Decimal value exported as String instead of Number
engine/org.eclipse.birt.report.engine.emitter.prototype.excel/src/org/eclipse/birt/report/engine/emitter/excel/ExcelWriter.java
writer.attribute( "ss:Color", color );
		}
		writer.closeTag( "Border" );
	}
	public void writeFont( String fontName, String size, String bold,
			String italic, String strikeThrough, String underline, String color )
	{
		writer.openTag( "Font" );
		if ( isValid( fontName ) )
		{
			writer.attribute( "ss:FontName", fontName );
		}
		writer.attribute( "ss:Size", size );
		writer.attribute( "ss:Bold", bold );
		writer.attribute( "ss:Italic", italic );
		writer.attribute( "ss:StrikeThrough", strikeThrough );
		
		if(!"0".equalsIgnoreCase( underline )) {
			writer.attribute( "ss:Underline", "Single" );
		}	
		if ( isValid( color ) )
		{
			writer.attribute( "ss:Color", color );
		}
		writer.closeTag( "Font" );
	}
	public void writeBackGroudColor( String bgColor )
	{
		if ( isValid( bgColor ) )
		{