function getDocSize() {
	var myWidth = 0, myHeight = 0;
	if( typeof( window.innerWidth ) == "number" ) {
		//Non-IE
		myWidth = window.innerWidth;
		myHeight = window.innerHeight;
	} else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
		//IE 6+ in 'standards compliant mode'
		myWidth = document.documentElement.clientWidth;
		myHeight = document.documentElement.clientHeight;
	} else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
		//IE 4 compatible
		myWidth = document.body.clientWidth;
		myHeight = document.body.clientHeight;
	}
	return [ myWidth, myHeight ];
}


function mailOn() { window.document.getElementById("envelope").style.backgroundPosition="bottom left"; }
function mailOff() { window.document.getElementById("envelope").style.backgroundPosition="top left"; }


function arrowOn(x) { window.document.getElementById("arrow"+x).className="arrow"+x+"_b"; }
function arrowOff(x) { window.document.getElementById("arrow"+x).className="arrow"+x+"_a"; }
function centerArrows() {
	size=getDocSize();
	window.document.getElementById("arrowLeft").style.top=String(Math.floor(size[1]/2)-arrowHeight)+"px";
	window.document.getElementById("arrowRight").style.top=window.document.getElementById("arrowLeft").style.top;
}