Best I can tell if your footer is affecting your div that is not in the footer, then you need to separate the two. If you want a fixed footer on every page as Paulie_D asked then put it in its own footer div and give it a; position: fixed; and set your ‘top’ and ‘left’ properties accordingly. Then your footer will be constant and your main content can change. as far as height goes, make sure your using the box model correctly with your padding and margins then say either height: (insert px, em, or %), or max-height: (insert px, em, or %). I hope this helps. As a new poster like yourself I find it very helpful to use codepen and link to your problem page if possible so that people understand your question better.
Thank you so much for your special comments i appreciate it.. i will try with sticky footer so if i use this does my middle portion will be dynamic? how ever my middle portion will be increased or decreased footer will also stay with it???