ABAP Object (calc) program

Question

hi all,
i am trying to create calc i had write program it's working but not in full performence is will attach the program pls give me complete advise .
regards.
hari rayala.
PROGRAM FOR CALC
MODULE USER_COMMAND_0100 INPUT.
CASE OK_CODE.
**FOR NUM1********************
WHEN 'NUM1'.
RESULT = 1.
v1 = RESULT.
IF VAL1 = 0.
VAL1 = V1.
ELSE.
VAL2 = V1.
ENDIF.
**FOR NUM2********************
WHEN 'NUM2'.
RESULT = 2.
V2 = RESULT.
IF VAL1 = 0.
VAL1 = V2.
ELSE. VAL2 = V2.
v2 = RESULT.
ENDIF.
**FOR NUM3********************
WHEN 'NUM3'.
RESULT = 3.
IF VAL1 = 0.
VAL1 = V3.
ELSE. VAL2 = V3.
v3 = RESULT.
ENDIF.
**FOR NUM4********************
WHEN 'NUM4'.
RESULT = 4.
  IF VAL1 = 0.
VAL1 = V4.
ELSE. VAL2 = V4.
v4 = RESULT.
ENDIF.
**FOR NUM5********************
WHEN 'NUM5'.
RESULT = 5.
  IF VAL1 = 0.
VAL1 = V5.
ELSE. VAL2 = V5.
v5 = RESULT.
ENDIF.
**FOR NUM6********************
WHEN 'NUM6'.
RESULT = 6.
  IF VAL1 = 0.
VAL1 = V6.
ELSE. VAL2 = V6.
v6 = RESULT.
ENDIF.
**FOR NUM7********************
WHEN 'NUM7'.
RESULT = 7.
  IF VAL1 = 0.
VAL1 = V7.
ELSE .
VAL2 = V7.
v7 = RESULT.
ENDIF.
**FOR NUM8********************
WHEN 'NUM8'.
RESULT = 8.
IF VAL1 = 0.
VAL1 = V8.
ELSE. VAL2 = V8.
v8 = RESULT.
ENDIF.
**FOR NUM9********************
WHEN 'NUM9'.
RESULT = 9.
IF VAL1 = 0.
VAL1 = V9.
ELSE. VAL2 = V9.
v9 = RESULT.
ENDIF.
**FOR NUM0********************
WHEN 'NUM0'.
RESULT = 0.
  IF VAL1 = 0.
VAL1 = V0.
ELSE. VAL2 = V0.
v0 = RESULT.
ENDIF.
**FOR ADDITION****************
WHEN 'ADD'.
RESULT1 = VAL1 + VAL2.
**FOR MULTIPLICATION**********
WHEN 'MUL'.
RESULT1 = VAL1 * VAL2.
**FOR DIVISION****************
WHEN 'DIVIDE'.
RESULT1 = VAL1 / VAL2.
**FOR SUBSTRACTION************
when 'SUT'.
RESULT1 = VAL1 - VAL2.
WHEN 'CLEAR'.
CLEAR RESULT.
CLEAR : VAL1, VAL2 .
**FOR RESTUL******************
when 'ENTER'.
RESULT = RESULT1 .
ENDCASE.
ENDMODULE.                 " USER_COMMAND_0100  INPUT

Answer 1

Sort of like this?
case ok_code.
  when 'NUM1' or 'NUM2' or 'NUM3' or 'NUM4' or 'NUM5'
    or 'NUM6' or 'NUM7' or 'NUM8' or 'NUM9' or 'NUM0'.
    data: field_name(20) type c.
    field-symbols: <fs>.
    concatenate 'V' ok_code+3(1) into field_name.
    assign (field_name) to <fs>.
    result = ok_code+3(1).
    <fs> = result.
    if val1 = 0.
      val1 = <fs>.
    else.
      val2 = <fs>.
    endif.
***FOR ADDITION*****************
  when 'ADD'.
    result1 = val1 + val2.
***FOR MULTIPLICATION***********
  when 'MUL'.
    result1 = val1 * val2.
***FOR DIVISION*****************
  when 'DIVIDE'.
    result1 = val1 / val2.
***FOR SUBSTRACTION*************
  when 'SUT'.
    result1 = val1 - val2.
  when 'CLEAR'.
    clear result.
    clear : val1, val2 .
***FOR RESTUL*******************
  when 'ENTER'.
    result = result1 .
endcase.
Regards,
RIch Heilman