รบกวนพี่ๆช่วยเรื่อง google map api key v3 ไม่แสดงแผนที่

<script type="text/javascript">   
 var locations = [   
    ['ทดสอบร้านอาหาร', 15.09234482843765, 104.30643081665039, 1]];    
var map = new google.maps.Map(document.getElementById('map'), {      
zoom: 13,      
center: new google.maps.LatLng(15.09234482843765, 104.30643081665039),      
mapTypeId: google.maps.MapTypeId.ROADMAP   
});    
var infowindow = new google.maps.InfoWindow();    
var marker, i;    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   
});     

google.maps.event.addListener(marker, 'click', (function(marker, i) {        
return function() {         
 infowindow.setContent(locations[i][0]);          
 infowindow.open(map, marker);        
 }      
 })
 (marker, i));    
 }  
 </script>