XML : XML Parsing Error: mismatched tagin PHP XML File

I have the following PHP file.

  <?php      header('Content-Type: text/xml');      echo '<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>';      session_start();      echo '<response>';      $email = $_GET['person'];      $UserEmail = $_SESSION['login'];        $conn = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);      mysql_select_db(DB_DATABSE, $conn);        $sql_find = mysql_query("SELECT * FROM Users WHERE UserEmail='".$email."' LIMIT 1");        if(mysql_fetch_array($sql_find)) {          $sql_add = "UPDATE Users SET Contacts = concat(Contacts, ';', '".$email."') WHERE UserEmail = '".$UserEmail."'";          if (mysql_query($conn, $sql_add)) {             echo array( 'found' => true, 'msg' => "Person added to your record");          }           else {             echo array( 'found' => false, 'msg' => "Error adding person to your record \n Is the person emails' correct?");          }        }      else {          echo array( 'found' => false, 'msg' => "We couldn't find the user in our databases.");      }        echo '</response>';  ?>    

I use Ajax to add data to MySql and return the result to front-end. The problem is that even if the SQL code work when I tested to my server PhPAdmin, it shows me the following error:

  XML Parsing Error: mismatched tag. Expected: </br>.  Location: http://secretsea.comli.com/lib/addPerson.php  Line Number 3, Column 261:<br><table border='1' cellpadding='2' bgcolor='#FFFFDF' bordercolor='#E8B900' align='center'><tr><td><div align='center'><a href='http://www.000webhost.com/'><font face='Arial' size='1' color='#000000'>Free Web Hosting</font></a></div></td></tr></table>Array</response>  --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------^    

I tried to find a solution on the website and other resourses, but I couldn't understand what am I doing wrong. Is my syntax wrong?