Hi, 

I have poted this issue in Ajax Forum about 10 days ago but I haven't received any reply, that's the reason why I re-posting it here hoping that some would help with this: 

In my form i have a panel containing some controls that are postback enabled as well as a dropdownlist and this panel is inside an updatepanel. the problem is that the page still flicks and flashes when one of the controls inside the panel causes a postback, and when I delete the dropdownlist control from my panel everything works fine and the page doesn't flash on postback. So how can I fix this!? and I tried to register this dropdownlist as a trigger in my updatepanel but I can see the dropdownlist or even my panel in the triggers list!. 

Thanks.     

Hi,

It will be more relevant posting your code here to help you. 

set dropdown is autopostback property to false.. and try..

hope this will help..

Well the dropdownlist is already autopostback=false but still the same problem, and it want help since I will need it to autopostback anyway!!

Thanks.

Use UpdatePanel Trigger

http://www.asp.net/AJAX/Documentation/Live/tutorials/ExclusiveAsyncPostback.aspx

For whatever reason, I've found that not specifying an EventName on triggers sometimes cures this problem.  Give that a try.

For addtional reference

http://asp.net/ajax/documentation/live/overview/UpdatePanelOverview.aspx

http://msdn2.microsoft.com/en-us/magazine/cc163363.aspx
http://msdn2.microsoft.com/en-us/magazine/cc163413.aspx

Just check for web.config also

http://asp.net/AJAX/Documentation/Live/InstallingASPNETAJAX.aspx

http://asp.net/AJAX/Documentation/Live/ConfiguringASPNETAJAX.aspx