Embedding an iframe size problem

I am trying to embed an iframe and only part of it is showing. I have several inches inside the template frame remaining, but the embed has a scroll bar at the bottom of the screen. It does not look good and I have to get this corrected.

What do I need to do? Is there a way for me to enlarge the template frame or increase the margins within it?

This embed is the main purpose of me creating this particular site so it has to work.

Thanks