function switchLayer1() { if (!document.theform.layers1.checked) { map.removeOverlay(layerLowExit); } else { map.addOverlay(layerLowExit); }
}
function switchLayer2() { if (!document.theform.layers2.checked) { map.removeOverlay(layerHighExit); } else { map.addOverlay(layerHighExit); } }
function switchLayer3() { if (!document.theform.layers3.checked) { map.removeOverlay(layerAll); } else { map.removeOverlay(neighborhoods); map.addOverlay(layerAll); map.addOverlay(neighborhoods); } }