How to use IF ELSE statement in Script

Hi,

I am trying to write a If condition in script as below

/: IF &QALS-ANZGEB& = 1

S1 Sample Size,,1

/: ELSEIF &QALS-ANZGEB& > 1 AND &QALS-ANZGEB& <= 15

S1 Sample Size,,2

/:ELSE

S1 Sample size,,3

ENDIF

But only the statement after ELSE is executed ..Can you please tell me whats the error in the above.

I tired using '1' but still sample size 3 is printed.