insert 语句

下面一段代码,不知道错在什么地方
怎么加都加不上数据,
<?php
require("inc/conn.php");
require("inc/checkadmin.php");
$stu_name=$_POST["stu_name"];
$stu_sex=$_POST["stu_sex"];
$stu_email=$_POST["stu_email"];
$stu_address=$_POST["stu_address"];
$stu_phone=$_POST["stu_phone"];
$add_time=date("F-d-Y G:i:s");
$rec="insert into student(stu_name,stu_sex,stu_email,stu_address,add_time,stu_phone) values('$stu_name','$stu_sex','$stu_email','$stu_address','$add_time','$stu_phone')";
$result=mysql_query($rec);
echo "<script> alert('数据添加成功!');location.href='information.php';</script>";

?>