Incorrect position of calendar in Internet Explorer 7-10

Currently calendar position offset is get from document.body.scrollTop for IE,
but it not always works. Then offset should be get from: document.documentElement.scrollTop if it is defined

Edit file: /templates/protostar/index.php
Add following code before </body> closing tag:
<?php echo JHtml::_('calendar', null, 'calendar', 'calendar'); ?>
Open front-end in Internet Explorer 7 - 10.
Resize window that you will not see calendar field.
Scroll down to calendar field.
Click on calendar icon.
Calendar would open not next to field but at top of document.

See attached images on Code Tracker to understand how it works
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=32440