[jQuery] how to blockUI for whole document from iframe

[balavignesh]

Hello friends,

                While using ajax , i am blocking the UI part using the
following jquery ,

$(document).ajaxStart(function(){
                      $().blockUI({message: '<img src="/images-system/
loading.gif" />'})}).
                                      ajaxStop($.unblockUI);

        I am using this inside the iframe. So, while ajax request ,
the iframe document only blocked.
But i want to block the whole document.

Please suggest some idea.

Thanks & Regards,
Balavignesh