Access parent div from the child page

Question

I have three pages, two .aspx page and one .ascx page in parent child relationship. Page1.aspx->Page2.aspx->page3.aspx

Page1.aspx contains iframe inside div:

<script type="text/javascript">
    $(document).ready(function () {
        var getQueryString = function (field, url) {
            var href = url ? url : window.location.href;
            var reg = new RegExp('[?&]' + field + '=([^&#]*)', 'i');
            var string = reg.exec(href);
            return string ? string[1] : null;
        };
        var consoletype = getQueryString('ConsoleType');

        var role = getQueryString('role');


        var url = "/_layouts/Page2.aspx?Type=" + consoletype + "&role=" + role;


        $("#load").attr("src", url);
    });
</script>
<div id="loader" class="loading">
    Processing
    <img id="imgloader" src="../../_layouts/images/loadr.gif"
        style="display: none" alt="" />
    <iframe id="load" src="" width="1000px" height="400"></iframe>
</div>

Then in Page2.aspx i am registering .ascx page:

<%@ Register TagPrefix="Import" TagName="Import" Src="~/_controltemp/Page3.ascx" %>

Then in Page3.ascx i have my actual code. From this page i need to access the div present in Page1.aspx.

I need to achive this with javascript or with c# code. Note: These are all sharepoint application pages.

Please suggest the way to achieve this.