Need jquery expert to add small feature

I need someone to add a simple jquery on click event. Need to change the "bottom" position of an element when another element is clicked. Basically creating a mobile nav menu. When someone clicks the nav button, it inserts an extra menu below the footer. The existing footer is position:fixed bottom:0 . When the link is clicked, it needs to display:block a hidden div and move the footer up 75px. I wrote what I thought was correct but it doesn't seem to work. need super fast turnaround. should be a simple job. do not bid if you cannot complete quickly.