Resizing content in a UIScrollView

Question

I am creating a scrollview programmatically and adding subviews to it programmatically. The subviews are created programmatically as well.

I am just wondering how to rotate / resize the subview so that it remains visible in landscape mode.

I have set the scrollview to autorotateSubviews:YES and in my subview i have set the mask to be flexiblewidth|flexibleheight is this correct?

I am used to doing this in IB with the springs and struts section of the inspector.

Thanks