function centralisedContent() {
	if (self.innerHeight) {	 
		winWidth = self.innerWidth;
		winHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) {  
		winWidth = document.documentElement.clientWidth;
		winHeight = document.documentElement.clientHeight;
	} else if (document.body) {  
		winWidth = document.body.clientWidth;
		winHeight = document.body.clientHeight;
	}
	if (winWidth>950) document.getElementById("page").style.left = (winWidth-950)/2+'px';
	else document.getElementById("page").style.left = '0px';
}

var winWidth = 0;
var winHeight = 0;
var bgimages = new Array();
bgimages.push("bg01.jpg");
bgimages.push("bg02.jpg");
bgimages.push("bg03.jpg");
var rdm = Math.random();
var bgidx = Math.floor(rdm*bgimages.length);
document.body.style.backgroundImage = 'url(/pics/bg/'+bgimages[bgidx]+')';

centralisedContent();