ajax - modal popup reposition wihout using property RepositionMode- using JQuery

It took me 2 days to look for the best option for the dealing with the problems, related to the ajax modal popup which was dynamic i could not fix the height of the popup as it would fail to deal with the dynamic content inside the iframe which was being displayed inside the modal popup, we have one property Repositionmode which has four option like.


RepostionMode: RepositionMode allows to repostion the modalpopup when the web page is resized or scrolled. You can select the following values to adjust this property:

1. RepositionOnWindowResize
2. RepositionOnWindowResizeAndScroll
3. RepositionOnWindowScroll
4. None
   
   I tried to put the scroll bar a jerk to get my reposition but failed when there was no scroll bar,
   but  I had smart solution for this, Using jQuery , after the data gets filled in the Iframe , just hide and again dispaly the popup, this resolved my problem, its best solution.