echo Error on for Page Protected PHP page - php

Question

I have a protected page that requires you to login to access the page content.
Where can I put an else statement that echos "wrong username or wrong password"
if the user does not enter the exact user/password?
The PHP page
<?php
// Define your username and password
$username = "user";
$password = "password";
if ($_POST['txtUsername'] != $username || $_POST['txtPassword'] != $password) {
?>
<h1>Login</h1>
<form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label>User</label>
<input type="text" title="Enter your Username" name="txtUsername" />
<label>Password</label>
<input type="password" title="Enter your password" name="txtPassword" />
<input type="submit" name="Submit" value="Login" />
</form>
<?php
}
else {
?>
<p>This is the protected page. Your private content goes here.</p>
<?php
}
?>
** I have tried entering it after -- else { at the bottom of page
** I have tried entering it after -- if($_POST...$password) {
neither one worked. I attached a image to show you what I mean.
Thanks

Answer 1

It can also be solved by simply setting some validation flags and using those on your views. Using your own code structure template, the following might do the trick:
<?php
// Define your username and password
$username = "user";
$password = "password";
$hasError = true;
$hasSubmitted = false;
if (isset($_POST['Submit'])) {
$hasSubmitted = true;
if ($_POST['txtUsername'] != $username || $_POST['txtPassword'] != $password) {
$hasError = true;
} else {
$hasError = false;
}
}
if ($hasError):
?>
<h1>Login</h1>
<?php if ($hasSubmitted): ?>
<p>*You entered a wrong username or password</p>
<?php endif; ?>
<form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label>User</label><input type="text" title="Enter your Username" name="txtUsername" />
<label>Password</label><input type="password" title="Enter your password" name="txtPassword" />
<input type="submit" name="Submit" value="Login" />
</form>
<?php else: ?>
<p>This is the protected page. Your private content goes here.</p>
<?php endif; ?>

Answer 2

<?php
class ValidateUser
{
public static function Check($user,$pass)
{
$settings[] = ($user == $_POST['txtUsername'])? 1:0;
$settings[] = ($pass == $_POST['txtPassword'])? 1:0;
return (array_sum($settings) == 2)? true:false;
}
}
// if the username and passowrd match up
if(isset($_POST['txtUsername'])) {
$uservalid = ValidateUser::Check('hardcodeuser','hardcodepass');
}
// If user/pass not valid
if($uservalid !== true || !isset($uservalid)) { ?>
<h1>Login</h1>
<?php if(isset($uservalid) && $uservalid !== true) echo 'Invalid Login'; ?>
<form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label>User</label>
<input type="text" title="Enter your Username" name="txtUsername" />
<label>Password</label><input type="password" title="Enter your password" name="txtPassword" />
<input type="submit" name="Submit" value="Login" />
</form>
<?php }
else { ?>
<p>This is the protected page. Your private content goes here.</p>
<?php
} ?>

Answer 3

Try this and read the comment in the code
<?php
if ($_POST['txtUsername'] != $username || $_POST['txtPassword'] != $password) {
?>
<h1>Login</h1>
<form name="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label>User</label><input type="text" title="Enter your Username" name="txtUsername" />
<label>Password</label><input type="password" title="Enter your password" name="txtPassword" />
<input type="submit" name="Submit" value="Login" />
</form>
<?php
//adde these line to check weather its empty or not
if(!empty($_POST['txtUsername']) && empty($_POST['txtPassword']))
{
//this is complicated part you need check username and password. and they have to
//match.
// i cant help you here, cause i dont know from where you want to check username and password
//but i am giving you if statement.
//simple way you get the username from form, than check wether the username password matches, in the db or not, and if does not matches, we show the error message
//run the query
//check the result
//result return succes then ok
//else show the error
}
else
{
echo 'You need to enter your username and password';
}
}
else {
?>
<p>This is the protected page. Your private content goes here.</p>
<?php
}
?>

Answer 4

<?php
// Define your username and password
$username = "user";
$password = "password";
$loginPageTPL = <<< EOF
<!doctype html>
<html>
<head>
<title>Login</title>
</head>
<body>
<h1>Login</h1>
<form name="form" method="post" action="{% PHP_SELF %}">
{% ERROR_MESSAGES %}
<label for="username">User</label>
<input id="username" type="text" placeholder="Enter your Username" name="txtUsername" />
<label for="password">Password</label>
<input id="password" type="password" placeholder="Enter your password" name="txtPassword" />
<input type="submit" name="Submit" value="Login" />
</form>
</body>
</html>
EOF;
$loginPageTPL = str_replace('{% PHP_SELF %}', $_SERVER['PHP_SELF'], $loginPageTPL);
if ((isset($_POST['txtUsername'])) && (isset($_POST['txtPassword']))) {
if (($_POST['txtUsername'] == $username) && ($_POST['txtPassword'] == $password)) {
echo "your private content here";
return;
} else {
$loginPageTPL = str_replace('{% ERROR_MESSAGES %}', '<div style="color: red">* you entered a wrong username and password</div>', $loginPageTPL);
echo $loginPageTPL;
}
} else {
$loginPageTPL = str_replace('{% ERROR_MESSAGES %}', '', $loginPageTPL);
echo $loginPageTPL;
}