IF x > 10 THEN y := 4           IF x > 10 THEN BEGIN y := 4;
               ELSE y := 5;                               z := 5;
                                                    END
                                               ELSE y := 5;

  The ELSE clause always modifies the closest IF-THEN statement.

  Use caution to avoid logic errors in nested IF statements, as in
  the following:

     IF A = 1 THEN    {First IF}
        IF B<>1 THEN  {Second IF}
           C := 1
     ELSE             {Appears to modify first IF}
        C := 0;       {Actually modifies second IF}