Calling Functional module

Hi,

when iam calling functional modiule I am getting the errors,

REPORT ZAC_TAB25.

CALL FUNCTION 'ZAC_CALCULATE'.

EXPORTING

IM_NUM1 = P_NUM1,

IM_NUM2 = P_NUM2,

IM_OPER = P_OPER.

IMPORTING

EX_RESULT =

.

PARAMETERS:

P_NUM1 TYPE I,

P_NUM2 TYPE I,

P_OPER TYPE C.

DATA:

W_RESULT TYPE C.

Error iam getting is Comma without preceding colon (after EXPORTING ?).