function MM_showHideLayers() { //v6.0

  var locations = ['seattle', 'san leandro', 'salt lake', 'richmond'];

  for (i=0; i<locations.length; i++) {

    var divToHide = document.getElementById(locations[i]);

    divToHide.style.visibility = 'hidden';

  }

  var i,p,v,obj,args=MM_showHideLayers.arguments;

  for (i=0; i<(args.length-2); i+=3) if ((obj=MM_findObj(args[i]))!=null) { v=args[i+2];

    if (obj.style) { obj=obj.style; v=(v=='show')?'visible':(v=='hide')?'hidden':v; }

    obj.visibility=v; }

}