如何使用PHP将登录表单错误返回到同一页面？

我对PHP比较陌生,并且已经用尽互联网试图找到这个问题的答案.我看过无数的例子,但人们看起来与我的登录系统非常不同,我无法解密它.

到目前为止,这是我的代码：

的index.html

Meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
logo">
        videoedu.edu    PHP">
        Username: 

checklogin.PHP

PHP

$host = "localhost";
$username = "root";
$password = "";
$db_name = "test";
$tbl_name = "members";

MysqL_connect("$host","$username","$password")or die("Cannot connect.");
MysqL_select_db("$db_name")or die("Cannot select DB.");

$myusername=$_POST["myusername"];
$mypassword=$_POST["mypassword"];


    if ($myusername&&$mypassword)
    {

    $myusername = stripslashes($myusername);
    $mypassword = stripslashes($mypassword);
    $myusername = MysqL_real_escape_string($myusername);
    $mypassword = MysqL_real_escape_string($mypassword);

    $sql = "SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
    $result = MysqL_query($sql);

    $count = MysqL_num_rows($result);

    if($count == 1){
    session_register("myusername");
    session_register("mypassword"); 
    header("location:login_success.PHP");
        }
    else 
        {
    echo "Wrong Username or Password";
        }
    }

    else

    echo "You have left one or more fields blank.";

?>

login_success.PHP

Now logged in.logout.PHP>logout

logout.PHP

PHP

session_start();

session_destroy();

echo "You have been logged out,

我已经尝试将其插入index.html并将文件名更改为index.PHP.

$submit = $_POST["login"];

if($submit)
{

}

…但它始终会在页面底部不断显示其中一个错误(“用户名或密码错误”).

我想要它,以便如果用户输入错误的用户名或密码,或将所需字段留空,则错误将弹出在同一页面上,而不是转到一个新的丑陋,空白的PHP页面,顶部显示错误消息左手角落.

最佳答案

在checklogin.PHP中,不要回显错误,请使用：

die(header("location:index.html?loginFailed=true&reason=password"));

或者类似的东西,在你的index.html页面中,只需让PHP生成HTML消息,如下所示：

    PHP $reasons = array("password" => "Wrong Username or Password","blank" => "You have left one or more fields blank."); if ($_GET["loginFailed"]) echo $reasons[$_GET["reason"]]; ?>

此外,当您使用标头重定向页面时,请确保die()或exit(),否则脚本的其余部分将继续运行.