My script adds markers to the map. When I want remove the last I click back button http://tests.uk4u.pl/goomap/goomap_markers/ Everything works OK but I started something similar with poliline. After many possible changes of my code I cant achieve the same like with my markers. I want remove last line of poliline with back button. After removing last one I want to have possibility to start from this point like with my markers. Please help me cos I cant find solution anywhere and I tried last two days.

var testInput;
var path=[];
var map;
var mapOptions = {
        center: new google.maps.LatLng(53.153691, -2.011640),
        zoom: 15
    };

var poly;
var polyOptions = {
        strokeColor: 'red',
        strokeOpacity: 0.8,
        strokeWeight: 4
    };

function initialize() {

    testInput = document.getElementById('test_input');
    testInput.value = '';   

    map = new google.maps.Map(document.getElementById('map-canvas'),mapOptions);

    map.controls[google.maps.ControlPosition.TOP_LEFT].push(document.getElementById('menu'));

    poly = new google.maps.Polyline(polyOptions);

    google.maps.event.addListener(map, 'click', function(event) {


        poly.setMap(map);

        var myLatLng = event.latLng;
        var lat = myLatLng.lat();
        var lng = myLatLng.lng();

        addLatLng(event);

    });
    path = poly.getPath();
    function addLatLng(event) {

        path.push(event.latLng);
        testInput.value = path.toString();
    }   
}
function deleteMarker() {

        poly.setMap(null);//remove from map
        path = [];

}
google.maps.event.addDomListener(window, 'load', initialize);