UISplitviewcontroller - detailedView size on UIOrientation change?

Question

I am creating a uisplitview programmatically, like http://stackoverflow.com/questions/2757489/uisplitviewcontroller-programmtically-without-nib-xib-thank-you/2977885#2977885, I am also showing 2 tableview within the detailedview.

I am having difficulty getting the width of the detailedview to show the tableviews in the middle.

currently am using:

 CGRect leftRectView = CGRectMake(self.view.bounds.origin.x, self.view.bounds.origin.y, width, height);
 CGRect rightRectView = CGRectMake(width, self.view.bounds.origin.y, width, height);

where width and height stem from

self.view.frame.size

any pointers appreciated.

Cheers

Nik