Comparing strings does not work php
<?php
$user = $_POST['myusername'];
$pass = $_POST['mypassword'];
$file_handle = fopen("db.txt", "rb");
while (!feof($file_handle)){
    $line_of_text = fgets($file_handle);
    $parts = explode('=', $line_of_text);
    if($parts[0] == $user){
        echo $parts[0];
    }
    if($parts[1] == $pass){
        echo $parts[1];
    }
}
fclose($file_handle);
?>

if(trim($parts[0]) == trim($user)){
    echo $parts[0];
}
if(trim($parts[1]) == trim($pass)){
    echo $parts[1];
}