1. Iframe in the parent page

<iframe name="parentPage"></iframe>

2. Attributes of elements in child pages

<input type="text" id="date" data-dojo-type="dijit/form/DateTextBox" value="2013-11-12"/>

3. Take the median value of DateTextBox in the child page

var statisDate = window.frames["parentPage"].document.getElementById('date').value;