I have a simple AJAX TabContainer control on a page with 4 tab panels. When the user clicks the last tab I need a message box to flash up. This event needs to be enabled/disabled on the basis of a value in a database and so code behind control is required (I write in VB). Adding an OnClientClick event to the tabpanel stops the entire control from rendering, whether I do it on the page or in code-behind. What am I missing?