How can I disable the confirmation popup when navigating off of IM_MainForm.aspx? 

I am displaying the page in an iframe and get the popup ("Are you sure you want to navigate away from this page?  This would close the window and all conversations would be closed.  Press OK to to continue, or Cancel to stay on the current page.") upon refresh of the main page or when clicking on any other link on the main page.

Thanks,
Shawn