How to make a simple "Invalid name or Password?

[N0L1m1t5]

If a user enters either the wrong username or password, what would the code be to have "Invalid name or password" pop up on the same page?

[WebStyles]

popup? like in javascript popups?

 

echo '<script>alert("Invalid Username or Password");</script>';

 

? ? ?

[manix]

if you want a nice styled popup I recommend using jquery and ajax

[IrOnMaSk]

I'm taking a big GUESS 

<?php
     $check = mysql_query("select*from database where username = '$username' AND password = '$password'") or die(mysql_error());
     while($confirm = mysql_fetch_array($check))
      {
         if($username != $confirm['username'] && $password != $confirm['password'])
              {
                  echo "wow you don't even know your own username and password? go hurt yourself!!!";
               }
         else 
             {
                 header("Location: welcome.php")// redirect after successful longin
              }
       }
?>

the $username is the variable assigned username input by user

the $password is the vaiable assigned to password input by user