background color with div width

On the main page of my site, I have a "slogan box" with a width set to 40%. This is outlined and has a background color. In IE, it outlines and colors in the blank space up to 40%, the desired effect. But in Firefox and Mozilla, it outlines only up to where the text stops.

Here's the main css behind it:
#slogan
{
border-bottom:2px solid black;
border-right:2px solid black;
border-left:2px solid black;
background-color:#ABAABB;
font-family:comic sans ms;
width:40%;
}

Attactched is the screenshot from IE and firefox.

How can I make it look like it does in IE for all browsers (i.e., what is the correct code?)

The full code can be seen here.

try putting Display:Block in your CSS there
Hope that helped
~Zero

moved...

Yes, displayed:block works perfectly. Thanks.