Prevent Background Scrolling When Displaying Popup

One option is to temporarily set the overflow property to hidden on body, that will get rid of the scroll bars but causes a small flicker when the page is adjusted.

The other choice is to tap onto the $(window).scroll() event and return false from there. That will also cause a bit of flicker as the browser doesn't react that fast to the return false statement.

Your best bet is to move your click event handlers to a separate file and do the binding there:

$(function() {
    $('.emailPost').click(function() {
        $(window).scroll(function() { return false; });
        pageTracker._trackPageview('/onclick/emailquote');            
    });
});

That should prevent a page from scrolling. Remember to remove the bind after the dialog closes, otherwise the page won't be scrollable anymore! You can remove binds using:

$(window).unbind('scroll');

To hide the scrollbar of the body when opening the popup

document.body.style.overflow = "hidden";

and to revert back when closing the popup

document.body.style.overflow = "visible";