Extra white space underneath last DIV Tag

I have unwanted space here between the last DIV tag and the BODY tag for some reason. I can't work out why. I don't want this extra space at all. I'd prefer if my DIV#footer was flush against the edge of 开发者_StackOverflowthe bottom of the browser. I've applied a bright highlight background-colour to the body tag so it's easier to see the issue.

The page validates for HTML and CSS.

Can anyone explain what's going on and how I might solve ?

Many thanks

div#wrap has margin-bottom: 20px (styles.css:46). Removing that appears to fix it.

div#wrap has a bottom-margin. Remove it and it will be ok.

You have a value of 20px at bottom

div#wrap {
    background-color:#FFFFFF;
    margin:0 auto **20**px;
    text-align:left;
    width:1000px;
}

make it

div#wrap {
    background-color:#FFFFFF;
    **margin:0 auto 0;**
    text-align:left;
    width:1000px;
}