How to use the unique index in phpMyadmin

I have this table and would like to use 2 fields with the index UNIQUE . How do I do it?

CREATE TABLE 'cpanel' (
  'id' int(11) NOT NULL,
  'thumb' text CHARACTER SET latin1 NOT NULL,
  'nome' text CHARACTER SET latin1 NOT NULL, 
  'email' text CHARACTER SET latin1 NOT NULL,**(esses são os campos)**
  'usuario' text CHARACTER SET latin1 NOT NULL,**(esses são os campos)**
  'nivel' text CHARACTER SET latin1 NOT NULL,
  'senha' text CHARACTER SET latin1 NOT NULL,
  'rep_senha' text CHARACTER SET latin1 NOT NULL,
  'data' timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  'url' text CHARACTER SET latin1 NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;