code: private String getNextChartJavascriptCall() {			
  		String data = getModel().getObject();
  		StringBuilder sb = new StringBuilder();				
  		sb.append("nextChart(").
  		   append(data).
  		   append(",\"").append(get("chartCanvas").getMarkupId()).
  		   append("\",\"").append(get("tipCanvas").getMarkupId()).	
  		   append("\",\"").append(width).	
  		   append("\",\"").append(height).		   
  		   append("\");");					
  		return sb.toString();
  	}
docs: nextChart(data, canvas, tipCanvas, width, height)