HELLP!!.. SQL - IF ELSE condition executed even though condition is never true

This is a simple sql statement used to print 2 different questions based on the choice entered. I notice that both statements are run even though the else or if condition is not true. The output printed is correct but i dont require the subsitution variable to promt user for entry if the statement is not true.

Thanks for your help people!

SET SERVEROUTPUT ON;
DECLARE 
 choice number(2) := '&Please_Enter_Choice';
 question varchar2(50);
BEGIN
 if choice = 1 then
  question := '&Whats_your_name?';
    else if choice = 2 then
     question := '&How_old_are_you?';
    END IF;
 END IF;
DBMS_OUTPUT.PUT_LINE(QUESTION);
END;