Perfect square no using function

DECLARE SUB SQU(N)
CLS
INPUT"ENTER ANY NO";N
CALL SQU(N)
END

SUB SQU(N)
S=SQU(N)
IF S=INT(S)THEN
PRINT"SUPPLIED NO IS PEFECT SQUARE"
ELSE
PRINT"SUPPLIED NO IS NO PERFECT SQUARE"
END IF
END SUB