var lay1;
	var lay2;
	var lay3;
	var lay4;
	function showlayer1() {
		clearTimeout(lay1);
		layer1.style.visibility='visible';
	}
	function hidelayer1() {
		lay1=setTimeout("hidelayer('layer1')",170);
	}
	function showlayer2() {
		clearTimeout(lay2);
		layer2.style.visibility='visible';
	}
	function hidelayer2() {
		lay2=setTimeout("hidelayer('layer2')",170);
	}
	function showlayer3() {
		clearTimeout(lay3);
		layer3.style.visibility='visible';
	}
	function hidelayer3() {
		lay3=setTimeout("hidelayer('layer3')",170);
	}

	function showlayer4() {
		clearTimeout(lay4);
		layer4.style.visibility='visible';
	}
	function hidelayer4() {
		lay4=setTimeout("hidelayer('layer4')",170);
	}

	
	function hidelayer(thelayer) {
		var a = document.getElementById(thelayer);
		a.style.visibility='hidden';
	}