Google maps delete all markers and then create new

I'm working to create a map, that by default loads the address and shows tha marker and place address in search box, that works fine. But I need to add the click event that will delete all markers first and then put the marker. As so far I was develop script that do all I need. But when user clicks on map, the searchbox gets place address but the old marker doesn't delete and new marker doesn't appears in the click location.

Here my working example code: https://jsfiddle.net/ehsLLg26/

Here my code:

        <script type="text/javascript">
                function initAutocomplete() {      
                    var myOptions = {
                        zoom: 15,
                        mapTypeId: google.maps.MapTypeId.ROADMAP, 
                        mapTypeControl: false
                    }                       

                    var map;
                    var marker;
                    var geocoder = new google.maps.Geocoder();
                    var address = document.getElementById('pac-input').value;
                    var infowindow = new google.maps.InfoWindow();                                              

                    geocoder.geocode( { address: address}, function(results, status) {
                        if (status == google.maps.GeocoderStatus.OK && results.length) {
                            if (status != google.maps.GeocoderStatus.ZERO_RESULTS) {

                                //create map
                                map = new google.maps.Map(document.getElementById("map"), myOptions);

                                //center map
                                map.setCenter(results[0].geometry.location);

                                //create marker
                                marker = new google.maps.Marker({
                                    position: results[0].geometry.location,
                                    map: map,
                                    title: document.getElementById('pac-input').value,
                                });                                                                       

                                // Create the search box and link it to the UI element.
                                var input = document.getElementById('pac-input');
                                var searchBox = new google.maps.places.SearchBox(input);
                                map.controls[google.maps.ControlPosition.TOP_LEFT].push(input);

                                // Bias the SearchBox results towards current maps viewport.
                                map.addListener('bounds_changed', function() {
                                    searchBox.setBounds(map.getBounds());
                                });

                                var markers = [];
                                // Listen for the event fired when the user selects a prediction and retrieve
                                // more details for that place.
                                searchBox.addListener('places_changed', function() {
                                    var places = searchBox.getPlaces();

                                    if (places.length == 0) {
                                        return;
                                    }    

                                    // Clear out the old markers.
                                    markers.forEach(function(marker) {
                                        marker.setMap(null);
                                    });
                                    marker.setMap(null);
                                    markers = [];

                                    // For each place, get the icon, name and location.
                                    var bounds = new google.maps.LatLngBounds();
                                    places.forEach(function(place) {
                                        var icon = {
                                            url: place.icon,
                                            size: new google.maps.Size(71, 71),
                                            origin: new google.maps.Point(0, 0),
                                            anchor: new google.maps.Point(17, 34),
                                            scaledSize: new google.maps.Size(25, 25)
                                        };

                                        // Create a marker for each place.
                                        markers.push(new google.maps.Marker({
                                            map: map,
                                            title: place.name,
                                            position: place.geometry.location
                                        }));

                                        if (place.geometry.viewport) {
                                            // Only geocodes have viewport.
                                            bounds.union(place.geometry.viewport);
                                        } else {
                                            bounds.extend(place.geometry.location);
                                        }
                                        });
                                    map.fitBounds(bounds);
                                });                                    

                                google.maps.event.addListener(map, 'click', function(event) {
                                    geocoder.geocode({
                                        'latLng': event.latLng
                                        }, function(results, status) {
                                            if (status == google.maps.GeocoderStatus.OK) {
                                                if (results[0]) {
                                                    document.getElementById('pac-input').value = results[0].formatted_address;                                                     
                                                }
                                            }
                                        });                                              
                                    placeMarker(event.latLng);
                                });                                                                                                          

                                function placeMarker(location) {                                        
                                    if (marker) {                                            
                                        marker.setPosition(location);                                           
                                    } else {
                                        marker = new google.maps.Marker({
                                            position: place.geometry.location, 
                                            map: map,
                                            title: place.name,
                                        });
                                    }
                                }                                    
                            }
                        } 
                        else {
                            $('#map').css({'height' : '15px'});
                            $('#map').html("Oops! address could not be found, please make sure the address is correct.");
                            resizeIframe();
                        }
                    });                        

                    function resizeIframe() {
                        var me = window.name;
                        if (me) {
                            var iframes = parent.document.getElementsByName(me);
                            if (iframes && iframes.length == 1) {
                                height = document.body.offsetHeight;
                                iframes[0].style.height = height + "px";
                            }
                        }
                    }
                    }
                </script>

How to reproduce issue: 1. Run the script 2. In search box type any address, then click enter 3. After the marker is added, click to nearby location Result: The old marker is not deleted and the new marker is not show. Expected result: Old marker deletes and the new marker appear.