map.markers is undefined Google Map API v3 - google-maps

Question

Ok so i have a map with some markers on it. There is a click event on the map that should get the closest marker however when the find_closest_marker(event) function runs it breaks on the map.markers.length saying that its undefined.
Here is a link to what im trying to http://jsfiddle.net/VyzFq/7/
Can anyone can please show me where I'm going wrong here.

Answer 1

Looks like there are a couple of problems:
1) the map.markers array hasn't been declared. declare it above the for loop, and push the markers onto the markers array.
...
var infowindow = new google.maps.InfoWindow();
var marker, i;
map.markers = []; // ADD THIS LINE
for (i = 0; i < locations.length; i++) {
marker = new google.maps.Marker({
position: new google.maps.LatLng(locations[i][1], locations[i][2]),
map: map
});
map.markers.push(marker); // ADD THIS LINE
...
2) the find_closest_point function can't see the map variable. move the find_closest_point function to the scope where you are adding the click event listener:
// CHANGE THIS LINE
google.maps.event.addListener(map, 'click', find_closest_marker);
// TO:
google.maps.event.addListener(map, 'click', function( event ) {
var lat = event.latLng.lat();
var lng = event.latLng.lng();
var R = 6371;
var distances = [];
var closest = -1;
for( i=0;i<map.markers.length; i++ ) {
var mlat = map.markers[i].position.lat();
var mlng = map.markers[i].position.lng();
var dLat = rad(mlat - lat);
var dLong = rad(mlng - lng);
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(rad(lat)) * Math.cos(rad(lat)) * Math.sin(dLong/2) * Math.sin(dLong/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = R * c;
distances[i] = d;
if ( closest == -1 || d < distances[closest] ) {
closest = i;
}
}
alert(map.markers[closest].title);
});