height 100% doesn't work, two divs inside div

Answer 1

It doesn't get the full height because the original container has no height. So 100% of nothing is still nothing.

If you give the parent div a height, then the 100% will take effect.

As seen here: http://jsfiddle.net/4JgA4/115/

    

    First to set height
    

    

    Why don't get the 100%