javascript - ImageMap type repeating itself -

i have posted image map type in site image repeats if zoom in , zoom out image. platform using joomla. editor jce editor.this how looks in web http://logic.al/qtu2/index.php/maptest. missing here ???

var moontypeoptions = {   gettileurl: function(coord, zoom) {       var normalizedcoord = getnormalizedcoord(coord, zoom);       if (!normalizedcoord) {         return null;       }       var bound = math.pow(2, zoom);       return 'http://i.imgur.com/9igczkv.png' +           '/' + zoom + '/' + normalizedcoord.x + '/' +           (bound - normalizedcoord.y - 1) + '.png';   },   tilesize: new google.maps.size(1130, 604),   maxzoom: 3,   minzoom: 0,   radius: 1738000,   name: 'moon' };  var moonmaptype = new google.maps.imagemaptype(moontypeoptions);  function initialize() {   var mylatlng = new google.maps.latlng(0, 0);   var mapoptions = {     center: mylatlng,     zoom: 5,     streetviewcontrol: false,     maptypecontroloptions: {       maptypeids: ['moon']     }   };    var map = new google.maps.map(document.getelementbyid('map-canvas'),       mapoptions);   map.maptypes.set('moon', moonmaptype);   map.setmaptypeid('moon'); }  // normalizes coords tiles repeat across x axis (horizontally) // standard google map tiles. function getnormalizedcoord(coord, zoom) {   var y = coord.y;   var x = coord.x;    // tile range in 1 direction range dependent on zoom level   // 0 = 1 tile, 1 = 2 tiles, 2 = 4 tiles, 3 = 8 tiles, etc   var tilerange = 1 << zoom;    // don't repeat across y-axis (vertically)   if (y < 0 || y >= tilerange) {     return null;   }    // repeat across x-axis   if (x < 0 || x >= tilerange) {     x = (x % tilerange + tilerange) % tilerange;   }    return {     x: x,     y: y   }; }  google.maps.event.adddomlistener(window, 'load', initialize);