[Solved] Page flash occurs with AJAXSettings

[newbie]

I have a button on my user control on click of which i open a radwindow.
I am getting return values from the radwindow to the calling page to populate in some controls.

I use this function to populate the controls:

function

PopulateValues(sender, returnValue)
{ 
var dataArg = '';
dataArg = dataArg + returnValue.AssignmentID;
dataArg = dataArg + '|' + returnValue.Staff;
dataArg = dataArg + '|' + returnValue.DocketNum;
__doPostBack("RadWindowPopup",dataArg);
}

This causes a page flash when the postback happens.

I tried using RadAJAXManagerProxy(I have a AJAXManager on my master page) to set the UpdatedControls but the page flashes even when I specify that.

How can I avoid the page flash?