How to make the background DIV only transparent using CSS

Question

I am using CSS attrubutes :

filter: alpha(opacity=90);    

opacity: .9;

to make the DIV transparent,

Answer 1

It's not possible, opacity is inherited by child nodes and you can't avoid this. To have only the parent transparent, you have to play with positioning (absolute) of the elements and their z-index

Answer 2

.modalBackground
    {

        filter: alpha(opacity=80);
        opacity: 0.8;
        z-index: 10000;
    }