Expand collapse or tree view functionality in reports

 Table: five continents and countries in it.

 I want expand collapse rows. For example in above table I want to show only five rows one for each continent with say plus button on its left. When user clicks on plus button it will expand and countries in that continents will be shown and plus button will changed to minus button. When user click on minus button all rows will collapse and so on...

I searched on this forum and internet. However, I am not able to get any useful information to expand collapse. How to achive this in Jasper reports? I am using iReports 3.6.2 as my JasperServer does not deploy reports created from new iReports.

Thanks.

 Wap Rau