Allow a div to cover the whole page instead of the area within the container

Question

I\'m trying to make a semi-transparent div cover the whole screen. I tried this:

#dimScreen
{
    width: 100%;
    height: 100%;
    background:rgba(255,255,         


        

Answer 1

#dimScreen{
 position:fixed;
 top:0px;
 left:0px;
 width:100%;
 height:100%;
}