hi thank u for ur reply
actually here my process is to load the city names in the drop down for the postal code entered in the text box
so i use the ajax update panel for the drop down and a javascript to do post back in which the textchanged event fired in the client side the drop down got populated.
this is working great for me..
but when i click any other elements like radio or button in the page the text changed event got fired once again the drop down list got populated again and so the selected value was not retained in the drop down ...
here is my sample code
aspx
------
<ajax:updatepanel id="update" runat="server">
<contentTemplate>
<table>
<tr>
<td>
<asp:TextBox ID="BillToPostalCode" runat="server" EnableViewState="false" Width="90px"
onkeyup="javascript:RefreshBillingAddress();" MaxLength="10" ValidationGroup="OPC"
onchange="markRed(this)" OnTextChanged="BillToPostalCode_textChanged" AutoPostBack="false"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:UpdatePanel ID="Update1" runat="server" >
<ContentTemplate>
<asp:DropDownList ID="drp_billToSubhurb_New" runat="server" Width="200px"
OnSelectedIndexChanged="drp_billToSubhurb_New_selectedIndexChanged" EnableViewState="true" >
</asp:DropDownList>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="BillToPostalCode" />
</Triggers>
</asp:UpdatePanel>
</td>
</tr>
<tr>
.
.
.
other form elements like radio buttons , text fields , buttons
.
.
.
.
.
</tr>
</table>
</contentTemplate>
</ajax:updatepanel>
in cs page
-----------
</td></tr><tr>........</tr></table></contentTemplate></ajax:updatepanel>in cs page-----------
protected void BillToPostalCode_textChanged(object sender, EventArgs e)
{
// bind the drop down based on the text box value
}
thanks in advance
muthu