I have just started using AJAX and have a Dropdown inside an AJAX UpdatePanel (see attach code). I thought the concept of the UpdatePanel was it would control the postback for its enclosed components without causing a postback of the entire page.
But, when I make a selectin in the Dropdown, the entire page "flashes" as it is refreshed. What am I doing wrong?
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<asp:AsyncPostBackTrigger ControlID="DropDownList2" EventName="SelectedIndexChanged" />
<asp:DropDownList ID="DropDownList2" runat="server" DataSourceID="sqlds_contractor"
DataTextField="Company_Name" DataValueField="ID" OnSelectedIndexChanged="DropDownList2_SelectedIndexChanged"