Iframe for Chat

Hi,

I need to have a vertical responsive iframe for justblab chat I want to embed. The chat does not have a fixed height or ratio like a video so I need the iframe to recognize the browser height and adjust to fit. Getting iframes to adjust to 100% width is easy to achieve but setting the vertical height for 100% results in only a few pixels height of chat. I would need this to be responsive for both computer and mobile. Is it possible to achieve this with your plugin? Thanks in advance.
Brian