Can i used Client Callback without Postback with connect to Database

Hi,
You can use ajax for this purpose you need to add Jquery library.
after it you can modify following code lines according to your requirements.
$.ajax({
type:
"POST",
url:
"AjaxCalls.aspx?functionName=addfavourite",
data:
'userID=\''+userID+ '\'&categoryID='+ selecttedategoryId ,
success: onSuccsess
});
}
function onSuccsess(result) {
finnd control ans show result
}
and on ajaxcalls.aspx page:

Ad this code in page_load event
Response.Expires = -1; //required to keep the page from being un cached on the client's browser
string switch_on = Request.QueryString["functionName"].ToLower();
switch (switch_on)
{
case "konter":
string userID= Request.Form["userID"];
string categoryID = Request.Form["categoryID"];
//insert command for this data
ResponseHandling("data saved successfully");
}


//Create function which handle ajax response.
private void ResponseHandling(string result)
{
Response.Clear(); //clears the existing HTML
Response.ContentType = "text/plain"; //change content type
Response.Write(result);//Send back the fetched value to calling function.
Response.End();
}

Thanks
Mahessh K. Sharma
http://www.helpondesk.blogspot.com

If you donot want to use ajax but your page is work like ajax update panel you use ICallbackEventHandler interface.

how use icallbackevnethandler is view following site:-
http://msdn.microsoft.com/en-us/library/system.web.ui.icallbackeventhandler.aspx
http://www.codeproject.com/KB/aspnet/ICallbackEventHandler.aspx