var oldLayer;
function archiveLayerSwitch(layerName) {
// Hide the last layer displayed
if(document.getElementById(oldLayer) && oldLayer != layerName) {
document.getElementById(oldLayer).className = "archiveHidden";
}
// Store the layer for next time
oldLayer = layerName;
// Hide or display the new layer
if(document.getElementById(layerName)) {
if(document.getElementById(layerName).className == "archiveVisible") {
document.getElementById(layerName).className = "archiveHidden";
} else {
document.getElementById(layerName).className = "archiveVisible";
}
}
}