// JavaScript Document

function toggleLayer(whichLayer) {
		var style1 = document.getElementById(whichLayer).style;
		style1.display = ("none");
	}
function toggleLayer2(whichLayer) {
		var style2 = document.getElementById(whichLayer).style;
		style2.display = ("block");
	}
	
	
function changeImage1() {
	document.getElementById('tab-earth').style.backgroundImage = "url(images/tab-earth-active.gif)";
    document.getElementById('tab-life').style.backgroundImage = "url(images/tab-life-inactive.gif)";
	document.getElementById('tab-physical').style.backgroundImage = "url(images/tab-life-inactive.gif)";
    }
	
function changeImage2() {
	document.getElementById('tab-earth').style.backgroundImage = "url(images/tab-earth-inactive.gif)";
    document.getElementById('tab-life').style.backgroundImage = "url(images/tab-life-active.gif)";
	document.getElementById('tab-physical').style.backgroundImage = "url(images/tab-physical-inactive.gif)";
    }
	
function changeImage3() {
	document.getElementById('tab-earth').style.backgroundImage = "url(images/tab-earth-inactive.gif)";
    document.getElementById('tab-life').style.backgroundImage = "url(images/tab-life-inactive.gif)";
	document.getElementById('tab-physical').style.backgroundImage = "url(images/tab-physical-active.gif)";
    }