Question

I am successfully creating a marker on click however, using the following code, I get a new marker with every click, I only ever want one marker added and if someone clicks more than once I would like it to move the existing marker to the new position Can anyone help here is the code

 function placeMarker(location) {
        var clickedLocation = new google.maps.LatLng(location);
        var marker = new google.maps.Marker({
            position: location,
            map: map
        });
    }

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

Answer 1

var marker;

function placeMarker(location) {
  if ( marker ) {
    marker.setPosition(location);
  } else {
    marker = new google.maps.Marker({
      position: location,
      map: map
    });
  }
}

google.maps.event.addListener(map, 'click', function(event) {
  placeMarker(event.latLng);
});

You have to work on the same marker all the time – do not create new ones.
Here you have a global variable marker and in placeMarker function you assign marker to this variable first time. Next time it checks that marker exists already and then just changes its position.