Undefined variable on POST - php

Question

I looked trough your pages and fixed my undefined index on username and password but now I get undefined variable. I had more code but decided to simplify it for the sake of testing and just echo it to see if anything changes and it doesn't.
<?php
if (isset($_POST['submit'])){
$uname = isset($_POST['username']);
$pass = isset($_POST['password']);
}
echo $uname;
echo $password;
?>
I get this:
Notice: Undefined variable: uname in C:\xampp\htdocs\8\login.php on line 7
Notice: Undefined variable: pass in C:\xampp\htdocs\8\login.php on
line 8
I do not really understand what's wrong here. If needed here is my form page html.
<form id="login" method="post" action="login.php">
<div id="loginon">
<label for="username" style="color:#0F0; font-family:Arial, Helvetica, sans-serif;" >Username: </label>
<input type="text" id="username" name="username" />
<br />
<br />
<label for="password" style="color:#0F0; size:auto; font-family:Arial, Helvetica, sans-serif;">Password: </label>
<input type="password" id="password" name="password" />
<br />
<br />
<input type="image" src="http://www.clker.com/cliparts/2/G/4/v/K/E/submit-hi.png" border="0" width="180px" height="80px" alt="Submit" />
</div>
</form>
</body>
EDIT:
The further problem is connected to this so I think I am allowed to post it here.
if($username == "pikachu" || "cloud") {
$ucheck = "dobar";
} else {
$ucheck = "los";
}
if ($password == "123123" || "132132") {
$pcheck = "topar";
} else {
$pcheck = "losh";
}
if($ucheck == "dobar" && $pcheck == "topar") {
echo "Najjaci si!";
}
elseif ($ucheck == "dobar" && $pcheck == "losh") {
echo "Wimp.";
} elseif ($ucheck == "los" && $pcheck == "topar") {
echo "Fish.";
}
The problem is that it always echoes out "Najjaci si" no matter what I type in the previous form. Any ideas?

Answer 1

Since you have the variable decleration inside a logic (If), there is a chance that the variables are not set at all.
Try this
<?php
if (isset($_POST['submit'])){
$uname = isset($_POST['username']);
$pass = isset($_POST['password']);
echo $uname;
echo $pass;
} else {
echo "No submit detected!";
}
?>
It also doesen't look like if you have an actual element named submit.
Try adding this:
<input type="submit" name="submit" value="Send my form" />
Now, your form contains an element named "submit" which will be send as a post parameter when the form is submitted.
I myself, in need of a framework, like doing like this:
$username = ( isset($_POST["username"]) && $_POST["username"] != "" ? $_POST["username"] : false );
$password = ( isset($_POST["password"]) && $_POST["password"] != "" ? $_POST["password"] : false );
if( !$username === false && !$password === false )
{
echo $username . " <br /> " . $password;
} else {
echo "No! :) ";
}

Answer 2

isset will check that variable is set or not and pass value in 0 or 1. So over here you need to do as
$uname = isset($_POST['username']) ? $_POST['username'] : '';
$pass = isset($_POST['password']) ? $_POST['password'] : '';
Notice: Undefined variable: pass in C:\xampp\htdocs\8\login.php on line 8
Its because you were echoing $password instead of $pass
Edited
Do it as
$uname = '';
$pass = '';
if (isset($_POST['submit'])){
$uname = isset($_POST['username']);
$pass = isset($_POST['password']);
}
echo $uname;
echo $pass;

Answer 3

Try this
In form
<form id="login" method="post" action="login.php">
<div id="loginon">
<label for="username" style="color:#0F0; font-family:Arial, Helvetica, sans-serif;" >Username: </label>
<input type="text" id="username" name="username" />
<br />
<br />
<label for="password" style="color:#0F0; size:auto; font-family:Arial, Helvetica, sans-serif;">Password: </label>
<input type="password" id="password" name="password" />
<br />
<br />
<input type="submit" name="submit"/>
</div>
</form>
</body>
In login.php
<?php
if (isset($_POST['submit']))
{
$uname = $_POST['username'];
$pass = $_POST['password'];
}
echo $uname;
echo $pass;
?>