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.openTag( "Data" );
		try
		{
			Integer.parseInt( txt );
			writer.attribute( "ss:Type", "Number" );
		}
		catch ( Exception e )
		{
			writer.attribute( "ss:Type", "String" );
		}
		writer.text( txt );
		writer.closeTag( "Data" );
	}
	public void startRow( )
	{
		writer.openTag( "Row" );
	}
	public void endRow( )
	{
		writer.closeTag( "Row" );
	}
	public void startCell( int cellindex, int colspan, int rowspan, int styleid,
			HyperlinkDef hyperLink )
	{
		writer.openTag( "Cell" );
		writer.attribute( "ss:Index", cellindex );
		writer.attribute( "ss:StyleID", styleid );
		
		if ( hyperLink != null )