說明：未定義指數誤差

Question

<form action='login.php' method='POST'> 
    Username: <input type='text' name='Username'><BR> 
    Password: <input type='password' name='Password'><BR> 
    <input type="checkbox" name="remember" > Rember Me 
    <input type='submit' value='Log in'> 
    <a href="reg.php"> Register </a> 

<?php 
session_start(); 
include 'db.php'; 

$Username = $_POST['Username']; 
$Password = $_POST['Password']; 

if ($Username&&$Password) 
{ 
$query = mysql_query("SELECT * From Users WHERE Username='$Username'"); 

$numrow = mysql_num_rows($query); 

if ($numrow!=0) 

{ 
    while ($row = mysql_fetch_assoc($query)) 
    { 
     $Username = $row['Username']; 
     $Password = $row['Password']; 
    } 

    // check to see if they match 
    if ($Username==$Username&&$Password==$Password) 
    { 
     echo "You're in. <a href='index.php'>Click</a> here to enter the member page"; 
     $_SESSION['Username']=$Username; 
    } 

    else 
     echo "Incorrect password"; 
} 
else 
    die("That user doesn't exist"); 

} 
else 
    die ("please enter a username and a password"); 

?> 

誤差即時得到是：

說明： 未定義指數：用戶名在/home/stud/0/1314683/public_html/MathsrUs/login.php在線路48上的通知：未定義指數：密碼在/home/stud/0/1314683/public_html/MathsrUs/login.php在線49

Answer 1

有一個在$ _ POST

$Username = $_POST['Username']; 

$Password = $_POST['Password']; 

檢查沒有數據，如果頁面獲得通過POST訪問，你可以ch eck如果用$ _SERVER ['REQUEST_METHOD']變量。