OBSOLETE - How to implement collapsible ASPxRoundPanel

Starting with version v2014 vol 1 (v14.1), this functionality is available out of the box:
S19663: ASPxRoundPanel - Implement the collapsible functionality

Simply set the ASPxRoundPanel.ShowCollapseButton property to True to activate it. Please refer to the Load Content on Demand demo for more information.

If you have version v14.1+ available, consider using the built-in functionality instead of the approach detailed below.
If you need further clarification, create a new ticket in our Support Center.

This sample demonstrates how to implement collapsible ASPxRoundPanel functionality.