jQuery On（）对div不起作用

I have an asp.net page with UpdatePanel and like to make a scroll event hander persist through Ajax calls. I got it working for input element change event (see last example), but I am struggle with the sroll event for the div element.

$(document).ready(function()
{

/* working event fires but not after ajax call */
$("#ctl00_cirsContent_divReportLeft").on("scroll", function() {
    alert("test scroll left");
});

/* this one does not work at all */
$(document).on("scroll", "#ctl00_cirsContent_divReportRight", function () {
    alert("Test scroll");

});

/* this one works both before and after ajax call */
$(document).on("change", "#ctl00_cirsContent_CtlCalendar1_txtDate", function () {
    alert("Test type");

});

});

What am I missing?

Thanks

Try to use $(window) instead of $(document):

$(window).on("scroll", "#ctl00_cirsContent_divReportRight", function () {
    alert("Test scroll");
});

Ended up with this solution using the pageLoad event rather than $(document).ready:

function pageLoad(sender, args)
{
   if (args.get_isPartialLoad())
   {
    registerScrollEvent();
   }
}

and this in registerScrollEvent

$("div[id$='divReportLeft']").scroll(function () { 
.... some code
   });