Oracle Forms

I am new to oracle forms. I want to use 'IF ELSEIF ELSE' condition for radio button. If i use only IF and ELSE condition then it works but when i try to use IF ELSEIF ELSE condition then i am getting an error on line 2 as:

Encounter the symbol ";" when expecting one of the following: if

Here is my below PL/SQL code:

IF UPPER(:TEST_BRAND.BRAND_NAME) = 'FNC' THEN
  MESSAGE('U HAVE SELECTED FNC BRAND');
ELSE IF UPPER(:TEST_BRAND.BRAND_NAME) = 'FONIC-mobile' THEN
  MESSAGE('U HAVE SELECTED FONIC-mobile BRAND');
ELSE
  MESSAGE('U HAVE SELECTED KFL BRAND');
END IF;