iFrame settings are:

<iframe height="800" frameborder="0" width="690" scrolling="auto" hideadminborder="False" src="www.crossdomain-site.com" id="dnn_ctr869_IFrame_htmIFrame"></iframe>

i have try 

alert( $("#dnn_ctr869_IFrame_htmIFrame").css('overflow-y') )

but i get: auto

even if vertical scrollbar is visible or not.

Please if someone can contact me with pvt mail for sharing link problem ...