CSS div positioning IE, Safari and Firefox

[PeteGilmour]

The site I'm working on is http://www.m23law.co.uk

I have finally managed to get it dislaying properly in IE and Safari, but now it's broken in Firefox. Does anyone have any idea what could be wrong?

/* Position Container*/

#container {
background: #FFFFFF;
display: table;
padding: 0px;
position: relative;
top: 0px;
left: 50%;
margin-left: -365px;
width: 780px;
height: 100%;
border-right: solid 2px #000066;
border-left: solid 2px #000066;
}

/* Position other elements */

#menu {
position: relative;
float: left;
width: 114px;
height: 100%;
text-align: left;
padding: 0px;
}

.header {
font-style: bold;
position: relative;
top: 0px;
height: 100px;
background-repeat: no-repeat;
text-align: right;
color: #330066;
padding: 0px;
padding-right: 10px;
margin: 0;
}

#contents{
position: relative;
display: block;
float: right;
width: 632px;
height: 100%;
text-align: justify;
padding: 15px;
}

#copyright {
display: block;
position: absolute;
bottom: 0px;
text-align: center;
font-size: 8pt;
width: 100%;
}

[drhowarddrfine]

You will never get IE to pretend to act like modern browsers without a proper doctype. See the article about doctypes above.