Good Evening

I am building a website using DIVs and CSS.

I have everything in a container DIV, which I want to centre on the page. The CSS is below:

Code:
#container{ 
	width: 100%;
	max-width: 1000px;
	width:expression(document.body.clientWidth > 1000? "1000px": "auto" );
	float: center;
	color: #fff;	
    margin-left: auto;
	margin-right:
...