<?php

 //数据库信息

 $servername = "localhost";

 $username = "root";

 $password = "****";

 $dbname="login";

 /*

  *  mysql_select_db('l');

  *  mysql_query('set names utf8');

  */

 //打开session

 session_start();

 //判断账号密码是否被赋值

 if (isset($_POST['user']) && isset($_POST['pass'])) {

     $user = $_POST['user'];

     $pass = $_POST['pass'];

     //建立一个数据库连接

     $conn = mysql_connect($servername,$username,$password);

     /* 测试

      * if($conn)

      *  echo "连接成功";

      *  else die("连接失败".mysql_error());

      */ }

     //检查是否启动并给出提示

     if (!$conn) {

         die("connection failed:" . $conn->connect_error);

     }

     //指定一个数据库

     $db_select=mysql_select_db($dbname,$conn);

     //验证内容是否与数据库记录吻合

     $sql_L = "SELECT * FROM l WHERE (username='$user') AND (password='$pass')";

     //执行上面的sql语句并赋值给$r

     $r = mysql_query($sql_L,$conn);

     //将查到的结果数赋值$result

     $result = mysql_num_rows($r);

     //判断是否有对应记录

     if ($result>0) {

         echo "<script type='text/javascript'>alert('欢迎')</script>";

     } else

         echo "<script type='text/javascript'>alert('密码错误')</script>";

     //关闭数据库连接

     mysql_close($conn);

 ?>