谷歌地图API V3未显示地图

好吧，我有一个PHP脚本，它可以处理文件上传，特别是KML文件，提取上传文件的中心点和位置，将这些细节保存在文本文件中，然后通过"头"加载另一个页面。然后，另一个页面使用AJAX调用来设置从文本文件收集的变量名，用于KML文件的位置和中心点，以便调用Google Maps API在地图上显示KML层。

这是应该发生的事情，但却什么都没有出现。我浏览我的KML文件，点击上传按钮，就会显示一个空白页面。当我检查我的服务器时，文件已上传，相关详细信息已写入各自的文本文件，因此当我尝试调用谷歌地图API时，显然出现了问题。

PHP上传和文件信息保存：

<?php
//Check that we have a file
if((!empty($_FILES["UploadedFile"])) && ($_FILES['UploadedFile']['error'] == 0)) {
  //Check if the file is JPEG image and it's size is less than 3Mb
  $filename = basename($_FILES['UploadedFile']['name']);
  $ext = substr($filename, strrpos($filename, '.') + 1);
  if (($ext == "kml") && ($_FILES["UploadedFile"]["size"] < 3145728)) {
    //Determine the path to which we want to save this file
      $newname = dirname(__FILE__).'/kml/'.$filename;
      //Check if the file with the same name is already exists on the server
      if (!file_exists($newname)) {
        //Attempt to move the uploaded file to it's new place
        if ((move_uploaded_file($_FILES['UploadedFile']['tmp_name'],$newname))) {
           findCenter($newname);
           saveName($newname);
        } else {
           echo "Error: A problem occurred during file upload!";
        }
      } else {
         echo "Error: File ".$_FILES["UploadedFile"]["name"]." already exists";
      }
  } else {
     echo "Error: Only .kml files under 3Mb are accepted for upload";
  }
} else {
 echo "Error: No file uploaded";
}
function findCenter($file) {
   $kmlContent = file_get_contents($file);
   $startName = "#sh_green-circle";
   $endName = "#sh_red-circle";
   $startCoords = getCoords($kmlContent, $startName);
   $endCoords = getCoords($kmlContent, $endName);
   $startLat = substr($startCoords, strrpos($startCoords, ',') +1);
   $startLong = substr($startCoords, 0, strrpos($startCoords, ','));
   $endLat = substr($endCoords, strrpos($endCoords, ',') +1);
   $endLong = substr($endCoords, 0, strrpos($endCoords, ','));
   $midLat = ($startLat+$endLat)/2;
   $midLong = ($startLong+$endLong)/2;
   $midCoord = "$midLat,$midLong";
   $saveCenter = "kmlcenter.txt";
   $fh = fopen($saveCenter, 'w') or die ("Can't create file");
   $stringData = $midCoord;
   fwrite($fh, $stringData);
   fclose($fh);
}
function getCoords($kml, $name) {
   $startSearch = strpos($kml, $name);
   $midSearch = strpos($kml, "<coordinates>", $startSearch+1);
   $endSearch = strpos($kml, "</coordinates>", $midSearch+1);
   $longlat = substr($kml, $midSearch+13, $endSearch-($midSearch+13));
   return $longlat;
}
function saveName($filename) {
   $saveFile = "kmlfilename.txt";
   $fh = fopen($saveFile, 'w') or die("Can't create file");
   $stringData = "$filename";
   fwrite($fh, $stringData);
   fclose($fh);
   header("Location: initgmaps.html");
}
?>

地图初始化：

<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB8P7CzxiwQFf-RdK9QVRpH9se8AsMSsjEsensor=false"></script>
<script type="text/javascript">
function initialize() {
  var kmlName = getName()
  var kmlCoords = getCoords()
  var mapcenter = new google.maps.LatLng(kmlCoords);
  var myOptions = {
    zoom: 11,
    center: mapcenter,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  }
  var map = new google.maps.Map(document.getElementById("infoArea"), myOptions);
  var kmlLayer = new google.maps.KmlLayer(kmlName);
  kmlLayer.setMap(map);
}
</script>

相关AJAX功能：

<script language="javascript" type="text/javascript">
<!-- 
//Browser Support Code
function getName(){
    var ajaxRequest;  // The variable that makes Ajax possible!
    var kmlName;
    try{
        // Opera 8.0+, Firefox, Safari
        ajaxRequest = new XMLHttpRequest();
    } catch (e){
        // Internet Explorer Browsers
        try{
            ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try{
                ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e){
                // Something went wrong
                alert("Your browser does not support AJAX.");
                return false;
            }
        }
    }
       // Create a function that will receive data sent from the server
       ajaxRequest.onreadystatechange = function(){
            if(ajaxRequest.readyState == 4 && ajaxRequest.status == 200){
               kmlName = ajaxRequest.responseText;   
               }
       }
       ajaxRequest.open("GET", "kmlfilename.txt", false);
       ajaxRequest.send(null);
}
//-->
<script language="javascript" type="text/javascript">
<!-- 
//Browser Support Code
function getCoords(){
    var ajaxRequest;  // The variable that makes Ajax possible!
    var kmlCoords;
    try{
        // Opera 8.0+, Firefox, Safari
        ajaxRequest = new XMLHttpRequest();
    } catch (e){
        // Internet Explorer Browsers
        try{
            ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try{
                ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e){
                // Something went wrong
                alert("Your browser does not support AJAX.");
                return false;
            }
        }
    }
       // Create a function that will receive data sent from the server
       ajaxRequest.onreadystatechange = function(){
            if(ajaxRequest.readyState == 4 && ajaxRequest.status == 200){
               kmlCoords = ajaxRequest.responseText;   
               }
       }
       ajaxRequest.open("GET", "kmlcenter.txt", false);
       ajaxRequest.send(null);
}
//-->

当然，在initgmaps.html的正文中，我有：

onload="initialize()"

infoArea是我的内联框架的ID。

有人能看到为什么它没有加载吗？我对网络开发完全陌生，边学习边学习，如果代码很糟糕，我很抱歉，我肯定我犯了一些明显的错误。非常感谢。