google markers are updating but not removing previous markers

Question

I am working on redo search functionality on map drag event. I am using php as server side language, What I do in this is that when I refresh my code it shows all restaurants in listing and all these restaurants in google map with markers. Now I click on redo search check box and drag map. for this I am using map dragend event, i call ajax function and fetch all restaurants with in the distance of 9 km from middle of the map. I get all records in listing and also in google map as a marker, but the problem is that it does not remove the markers of previous restaurants those are not showing now in listing after search I am also using marker.setMap(null). Here is my code for map.

var map;
var marker;
google.maps.event.addDomListener(window, 'load', initialize);
function initialize(){
    var bounds = new google.maps.LatLngBounds();
    map=new google.maps.Map(document.getElementById("map-canvas"));
    updateMarkers(bounds,map);

    google.maps.event.addDomListener(map,'dragend',function() {
        if($('#redo_search_in_map').is(":checked")){
            formlat = map.getCenter().lat();
            formlng = map.getCenter().lng();
            var type = $("#types").val();
            var keywords=new Array();
            $(".Check").each(function(){
                if($(this).is(":checked")){
                    keywords.push($(this).val());
                }
            }); 
            $.ajax({
                url:ajax_url+'listing/search_listings',
                data:{
                    'formlat':formlat,
                    'formlng':formlng,
                    'type':type,
                    'keywords':keywords
                },
                type:"get",
                success:function(resp)
                {   
                    $("#ajax_listing").html(resp);
                    deleteMarkers();
                    updateMarkers(bounds,map);
                    return false;
                },
                error: function()
                {
                    alert('error');
                }
            });
            return false;
        }
    })

}

function updateMarkers(bounds, map){
    <?php foreach($filterRecords as $key=>$records){ ?>
        var lat = '<?php echo $records['Listing']['latitude']; ?>';
        var longi = '<?php echo $records['Listing']['longitude']; ?>';
        var latlng = new google.maps.LatLng(lat, longi);
        marker = new google.maps.Marker({
            position:new google.maps.LatLng(lat,longi),
        });
        marker.setMap(map);
        bounds.extend(latlng);
    <?php } ?>
    map.fitBounds(bounds);
}

function deleteMarkers(){
    marker.setMap(null);
}

Answer 1

try this:

  setMapOnAll(null); // remove markers from map, but save them at source

or

  clearMarkers();
  markers = [];

source: google maps javascript api