向Access写一个新数据

向Access写一个新数据
$Qname      = trim($_POST["newadmin"]);
$Qpswd      = md5(trim($_POST["password"]));
$times      = 0;
$lastlogin  = date("Y-m-d H:i");
$sql = "SELECT * FROM manage where username = '{$Qname} '";
$rs = $conn->Execute($sql);
  if (!$rs->EOF){
   echo "<script>alert(\"该用户名已经存在\");window.history.go(-1)(\");</script>";
      
   exit();
   $rs->close();
  }
  else {
   $insql = "insert into manage(username,password,logintimes,lastlogin) values(".$Qname.",".$Qpswd.",".$times.",".$lastlogin.")";
  
    if ($conn->Execute($insql)){
      echo ("<script>alert(\"添加成功！\");window.history.go(-1);");
   }
  }
  $conn->close();
[url=]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\[/url]报错
Fatal error: Uncaught exception 'com_exception' with message '<b>Source:</b> Microsoft JET Database Engine<br/><b>Description:</b> INSERT INTO 语句的语法错误。' in E:\Apple\Apple\manager\savefile.php:25 Stack trace: #0 E:\Apple\Apple\manager\savefile.php(25): com->Execute('insert into man...') #1 {main} thrown in E:\Apple\Apple\manager\savefile.php on line 25

请高手指正下.

ps:俺是新手,对PHP与ACCESS的操作涵数(添加\删除..等)不是很清楚.请别BS..谢谢!