I've got this piece of code:
      if (self::$username == "Borsucza Łapa.") {
        die("tak");
      } else {
        echo self::$username . "<br />";
        echo "Borsucza Łapa.";
      }
The condition is not valid, and the output from else statement is:
Borsucza Łapa.
Borsucza �apa.
What's that sign and how to turn it to an Ł sign?
 
    