function set_positions(){
	
	var winW = 630, winH = 460;
	
	if (parseInt(navigator.appVersion)>3) {
		if (navigator.appName=="Netscape") {
			winW = window.innerWidth;
			winH = window.innerHeight;
		}
		if (navigator.appName.indexOf("Microsoft")!=-1) {
			winW = document.body.offsetWidth;
			winH = document.body.offsetHeight;
		}
	}
	var ref = 776;
	var upperWith = 255;
	var bottomPos = 0, upperPos = 500;
	 
	if (winW>776) {
		bottomPos = Math.round((winW/2)-(ref/2));
		upperPos = Math.round((winW/2)+(ref/2)-upperWith);
	}
	
	var upperDiv=document.getElementById('upper');
	upper.style.left=upperPos;

	var bottomDiv=document.getElementById('bottom');
	bottom.style.left=bottomPos;
	return true;
}


function showlayers(){
	var upper=document.getElementById('upper');
	var bottom=document.getElementById('bottom');
	upper.style.opacity='1';
	upper.style.visibility='visible';
	bottom.style.visibility='visible';

	return true;
}