how to create the perfect driving directions points using php and mysql [closed]

Question

//

  var directionDisplay;
  var directionsService = new google.maps.DirectionsService();
  var map;
  var side_bar_html = ""; 
  var gmarkers = [];


function load() {
  directionsDisplay = new google.maps.DirectionsRenderer(); 
  //directionsDisplay.setMap(map);
  var map = new google.maps.Map(document.getElementById("map"), {
    center: new google.maps.LatLng(11.342339,77.727497),
    zoom: 12,
    mapTypeId: 'roadmap'
  });
  directionsDisplay.setMap(map);
  var infoWindow = new google.maps.InfoWindow;
  var sidebar = document.getElementById('sidebar');
      var point = [];
      var point1 = [];
      var path2 = [];

  downloadUrl("support.php", function(data) {
    var xml = data.responseXML;
    var markers = xml.documentElement.getElementsByTagName("point");
    for (var i = 0; i < markers.length; i++) {
      var name = markers[i].getAttribute("s_name");
      var img5 = markers[i].getAttribute("image_type");
      var type = markers[i].getAttribute("type");
      point = new google.maps.LatLng(
          parseFloat(markers[i].getAttribute("lat")),
          parseFloat(markers[i].getAttribute("lng")));
      var html = "<b>" + type + "</b>";

      var image_in = "<img src='http://sundar.lan/tele3/images/"+ img5 + "'/>";

      var icon = type;
      var marker = new google.maps.Marker({
        map: map,
        position: point,
        draggable: true,
        icon: icon.icon
      });
     var name = '<h3>' + "Students :" +'</h3>'+'<h4>' + name +'</h4>';
     //var img = '<h3>' +'<b>' + img5 +  '</b>'+'</h3>';

     bindInfoWindow(marker, map, infoWindow, name,image_in);
     // var sidebarEntry = createSidebarEntry(marker, type);
     sidebar.appendChild(createSidebarEntry(marker,type));
    }


    for (var j = 0; j < markers.length; j++) {
      point1[j] = new google.maps.LatLng(
          parseFloat(markers[j].getAttribute("lat")),
          parseFloat(markers[j].getAttribute("lng")));
      var flight = new google.maps.Polyline({
              path: point1,
              strokeColor: '#FF0000',
              strokeOpacity: 1.0,
              strokeWeight:2
            });
     flight.setMap(map);
     console.log(point1);
     calcRoute(point1)
    }
  });

  function createSidebarEntry(marker,type) { 
  var div = document.createElement('div');
  var html = '<h2>' +'<b>' + type +  '</b>'+'</h2>';
  div.innerHTML = html;
  div.style.cursor = 'pointer';
  div.style.marginBottom = '5px'; 
  google.maps.event.addDomListener(div, 'click', function() {
    google.maps.event.trigger(marker, 'click');
  });
  google.maps.event.addDomListener(div, 'mouseover', function() { 
    div.style.backgroundColor = '#eee';
  });
  google.maps.event.addDomListener(div, 'mouseout', function() {
    div.style.backgroundColor = '#fff';
  });
  return div;
}
}


function calcRoute(path2) {
    //alert(path);
    //var start = document.getElementById('start').value;
    //var end = document.getElementById('end').value;
    for(var k=0; k<path2.length-1; k++) 
    { 
    //alert(k);
    var request = {
        origin:path2[k],
        destination:path2[k+1],
        travelMode: google.maps.DirectionsTravelMode.DRIVING
    };
    directionsService.route(request, function(response, status) {
      if (status == google.maps.DirectionsStatus.OK) {
        directionsDisplay.setDirections(response);
        //selected_path = selected_path.concat(results.routes[0].overview_path);
      }
      /*else {
  // alert an error message when the route could nog be calculated.
  if (status == 'ZERO_RESULTS') {
    alert('No route could be found between the origin and destination.');
  } else if (status == 'UNKNOWN_ERROR') {
    alert('A directions request could not be processed due to a server error. The request may succeed if you try again.');
  } else if (status == 'REQUEST_DENIED') {
    alert('This webpage is not allowed to use the directions service.');
  } else if (status == 'OVER_QUERY_LIMIT') {
    alert('The webpage has gone over the requests limit in too short a period of time.');
  } else if (status == 'NOT_FOUND') {
    alert('At least one of the origin, destination, or waypoints could not be geocoded.');
  } else if (status == 'INVALID_REQUEST') {
    alert('The DirectionsRequest provided was invalid.');        
  } else {
    alert("There was an unknown error in your request. Requeststatus: nn"+status);
  }
}*/
    });
    }
  }


function bindInfoWindow(marker,map, infoWindow, name,image_in) {
  google.maps.event.addListener(marker, 'click', function() {
    infoWindow.setContent(name + image_in);
    infoWindow.open(map, marker); 
  });
}

function downloadUrl(url, callback) {
  var request = window.ActiveXObject ?
      new ActiveXObject('Microsoft.XMLHTTP') :
      new XMLHttpRequest;

  request.onreadystatechange = function() {
    if (request.readyState == 4) {
      request.onreadystatechange = doNothing;
      callback(request, request.status);
    }
  };

  request.open('GET', url, true);
  request.send(null);
}

function doNothing() {}


//]]>

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