window.onload = function winResize(){
	var x,y;
	if(document.all){//IE—p
		x=document.body.clientWidth;
	}
	else{
		x=window.innerWidth;
	}
	if(x<800) {
		document.body.style.backgroundPosition = '-160px 0px';
	} else {
		document.body.style.backgroundPosition = 'top center';
	}
}
window.onresize = function winResize(){
	var x,y;
	if(document.all){//IE—p
		x=document.body.clientWidth;
	}
	else{
		x=window.innerWidth;
	}
	if(x<800) {
		document.body.style.backgroundPosition = '-160px 0px';
	} else {
		document.body.style.backgroundPosition = 'top center';
	}
}