Accessing Ajax/Dynamic checkboxes

How do I check all checkboxes which have been returned as part of an AJAX request?

I have a page which displays email message summaries (think gmail/yahoo/etc... inbox). Each summary has a checkbox associated with it so that my user could do any number of things with the message. At the top and bottom of the list is a "check all" option. I know how to bind delegate functions to the dynamic checkboxes, but I can't seemt to find any way to give my "Check All" button the ability to manipulate these dynamic elements. Exa开发者_C百科mple:

//get the list of messages
$.ajax({
    type: "POST",
    url: "GetMessages.asmx/GetMessagePreview",
    data: "{'FolderID': '5'}",
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (result) {
       //code here to create a checkbox row (checkbox, message title, etc...)
       var cbRow = '<input type="checkbox" class="msg_check" ...etc... />'
       //code here to insert to a div or other container   
}
 });

$("#selectAllButton").click( function(){
   ????? This is the blank I need filled in...
});

Any help would be greatly appreciated. Thank you.

If you are trying to make the elements that come with the ajax call to inherit the current state of the #selectAll checkbox, then you need to read that and apply it as you create the new elements.

so

$.ajax({
    type: "POST",
    url: "GetMessages.asmx/GetMessagePreview",
    data: "{'FolderID': '5'}",
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (result) {

       var currentState = $("#selectAllButton").is(':checked') ? 'checked' : '';

       //code here to create a checkbox row (checkbox, message title, etc...)
       var cbRow = '<input type="checkbox" class="msg_check" '+ currentState +' />';
       //code here to insert to a div or other container   
}
 });

$("#selectAllButton").click( function(){
   // the way you normally select your elements..
   $('.msg_check')....
});

It should be easy:

$("#selectAllButton").click( function(){
    if (this.checked)
        $('.msg_check').attr('checked', 'checked');
    else
        $('.msg_check').removeAttr('checked');
});

Edited: if you want to insert item in the same condition, as all other items (all checked/unchecked), do next:

// ...
var checked = $("#selectAllButton").is(':checked');
var cbRow = $('<input type="checkbox" class="msg_check" />');
cbRow.appendTo(list);
var checkbox = cbRow.find('.msg_check');

if (checked)
    checkbox.attr('checked', 'checked');
else
    checkbox.removeAttr('checked');
// ...