FAZIT7T57TS6ACL6M2EXD3WZ6S7IZNKT3DZCF7E6GPRDU6IVZDAQC
SZYDW2DG5Z7BR3ICKWDXVUNSMCDSXMYZUB6FQ4W2B2FVZJD6PULQC
ZWCTAZGLJZQNTYWTC2XQUKMILJF6JGDL5IND6QNYWK4FIGMLRFXAC
error($c, "Invalid or empty username.") if $username eq "";