function offGroup(type) {
      for (var i = 0; i < markerGroups[type].length; i++) {
        var marker = markerGroups[type][i];
        marker.hide();
      } 
    }
    function offLabels() {
      //var showLabels = document.getElementById("labelsCheckbox").checked;
      for (groupName in markerGroups) {
        for (var i = 0; i < markerGroups[groupName].length; i++) {
          var marker = markerGroups[groupName][i];
          marker.setLabelVisibility(false);
        }
      }
    }
    function onGroup(type) {
      for (var i = 0; i < markerGroups[type].length; i++) {
        var marker = markerGroups[type][i];
        marker.show();
      } 
    }
    function onLabels() {
      //var showLabels = document.getElementById("labelsCheckbox").checked;
      for (groupName in markerGroups) {
        for (var i = 0; i < markerGroups[groupName].length; i++) {
          var marker = markerGroups[groupName][i];
          marker.setLabelVisibility(true);
        }
      }
    }

// for labeledmarker 1.3 
    function toggleGroup(type) {
      for (var i = 0; i < markerGroups[type].length; i++) {
        var marker = markerGroups[type][i];
        if (marker.isHidden()) {
          marker.show();
        } else {
          marker.hide();
        }
      } 
    }
    function toggleLabels() {
      var showLabels = document.getElementById("labelsCheckbox").checked;
      for (groupName in markerGroups) {
        for (var i = 0; i < markerGroups[groupName].length; i++) {
          var marker = markerGroups[groupName][i];
          marker.setLabelVisibility(showLabels);
        }
      }
    }