Body width 960px and 2 divs one fixed left and other right - html

Question

I've been searching everywhere and can't find a good solution for this.
So I have two divs, same height, that divide the page in not equal parts, a smaller one ("Small") and a bigger one ("Bigger"). I want them both to have position: fixed. "Smaller" is okay and where I want it but I can't put "Bigger" fixed right with body width 960px. When I put right: 0 he puts the div outside of the body width 960px and that's not what I want.
Any ideas for this?
Here's the CSS:
.Bigger {
position: fixed;
margin: 0 auto;
top: 160px;
width: 700px;
height: 800px;
background-color: blue;
}
.Smaller {
position: fixed;
top: 160px;
margin: 0 auto;
width: 215px;
height: 800px;
background-color: blue;
}

Answer 1

So I'm assuming by body 960px, your meaning, a parent div(content wrapper) of the two other divs that is margin 0 auto to keep it centered.
Just use position absolute, it fixes the div to the parent. Position fixed fixes the div to the window... that is why it's appearing outside the parent div.
For example if your html is like
<div class="container">
<div class="Bigger">
</div>
<div class="Smaller">
</div>
</div>
you could have css like :
.container {
position: relative;
width: 960px;
margin: 0 auto;
}
.Bigger {
position: absolute;
top: 160px;
right: 0;
width: 700px;
height: 800px;
background-color: blue;
}
.Smaller {
position: absolute;
top: 160px;
left: 0;
width: 215px;
height: 800px;
background-color: blue;
}