Background issue

I am working on a site with a green background in the body element. I am using the box model. I am using a container centered.

My problem is when use a margin between the box elements the green background shows through in my container.I want the container background to be white

here is the css for the body and container

body{
background-image: url(body-bg.jpg);
background-repeat:no-repeat;

}

#container{
margin: 0 auto;
width: 980px;
background-color:#ffffff;
}

overflow:hidden;

in the css

Looks like you didn’t clear the floated content in #container. Adding overflow:hidden will cause the parent to contain its child floats automatically and is one method of clearing floats when you don’t need visible overflow.