How to Sort the report by clicking the column_header at runtime?

Hi,<br /><br />Im New to Crystal Reports.<br /><br />Im Using Crystal report server XI. and JSP<br /><br />I need to <strong>Sort</strong> the report by clicking the<strong> column_header</strong> at runtime.<br /><br />How to implement this ?<br /><br />Please help me.<br /><br />- Venkat.<br />