Question

i am working on google maps, what i want to do is to click on the map it add a marker to the map its working fine but the problem is that i need to move the same marker to a new place if i click some where else instead of new marker. and also when i click on any point it give me the address of that place in a text field

here is my code

   <script type="text/javascript">
var map;
var markersArray = [];

 function initialize() {
    var haightAshbury = new google.maps.LatLng(37.7699298, -122.4469157);
var mapOptions = {
    zoom: 7,
    center: haightAshbury,
    mapTypeId: google.maps.MapTypeId.ROADMAP
   };
   map =  new google.maps.Map(document.getElementById("map_canvas"), mapOptions);

    google.maps.event.addListenerOnce(map, 'click', function(event) {
    addMarker(event.latLng);
   });
   }

   function addMarker(location) {

   marker = new google.maps.Marker({
   position: location,
   map: map
   });
   markersArray.push(marker);
   }

   // Removes the overlays from the map, but keeps them in the array
   function clearOverlays() {

    if (markersArray) {
     for (i in markersArray) {
       markersArray[i].setMap(null);
      }
    }
  }

  }

Answer 1

You can call clearOverlays anytime you create a new marker.this way you hide the previous marker and only the new is shown.
another way is to have a var marker just as you have a var map. you can edit the markers position in addMarker.
as far as geocoding is concerned take a look at this