Extending Body To Cover Z-indexed Footer When There Isn't Enough Content

I'm having difficulty in getting the main portion of the body to extend over the top of the footer. I have tried several methods such as setting 100% heights to the divs like this

Solution 1:

you need to set all parent divs height to 100%.

Add this css:

html,body,#mainbodyholder,#mainbody{
    height: 100%;
}