How do we know, an Iframe has scrollbar, after it has been rendered..in IE6 or more

I have an Iframe with-in DIV with fixed width of say300px, and certailny the content of iframe which points to different source URL, has more width(> 300px), Obviously the Iframe shows the Scroll Bars: may be both horizontal and vertical.

It Ultimately depends on the content of the Iframe, to show the iframe scrollbars or not.

Is there any way to know dynamically/programatically, Using JavaScript that iframe has scrollBars ON or OFF.


Thank you in Advance.