如何解决此问题以在谷歌地图上显示标记？

I am working to display the markers on my website.For this purpose i am getting the data from sqlite3 database. Can you correct me where i am doing wrong?

I am getting this error in wamp server: error on line 1 at column 3: xmlParsePI : no target name

This is my code:

maps.php:

    <?php
   require("phpsqlajax_dbinfo.php");

    // Start XML file, create parent node
    $doc = new DOMDocument("1.0");  
    $node = $doc->createElement ("marker");
    $parnode = $doc->appendChild($node);

  // Opens a connection to a MySQL server

    class MyDB extends SQLite3   
    {
       function __construct()
     {
      $this->open('mytrip.db');

      }
       }
    $db = new MyDB();
    if(!$db){
       echo $db->lastErrorMsg();
     } else {

       }
     // Set the active MySQL database


       // Select all the rows in the markers table
       $query = "SELECT * FROM marker ";
       $resultt = $db->query($query);

       //if (!$result) {
      //  die('Invalid query: ' . mysql_error());
         //}

     header("Content-type: text/xml");

   // Iterate through the rows, adding XML nodes for each
   while ($row = $ret->fetchArray(SQLITE3_ASSOC)){
    // Add to XML document node
    $node = $doc->createElement("marker");
    $newnode = $parnode->appendChild($node);

     $newnode->set_attribute("city_id", $row['id']);
     $newnode->set_attribute("name", $row['name']);
     // $newnode->set_attribute("address", $row['address']);
      $newnode->set_attribute("latitude", $row['latitude']);
      $newnode->set_attribute("longitude", $row['longitude']);
      $newnode->set_attribute("type", $row['type']);
      }

     $xmlfile = $doc->dump_mem();
    echo $xmlfile;

     ?>

phpsqlajax_dbinfo.php

   <?
    $username="username";
    $password="password";
    $database="username-databaseName"
    ?>