Error in small program

Question

The following program shows error when I give input to Num1 and Num2 ,then press Add or Exit.It says "Invalid Format (Screen Error)" Any Help Please
REPORT  ZTODAY                                  .
data : num1 type i,
       num2 type i,
       NUM3 TYPE I,
       OK_CODE TYPE SY-UCOMM.
call screen 100.
*&      Module  USER_COMMAND_0100  INPUT
      text
MODULE USER_COMMAND_0100 INPUT.
case OK_CODE.
WHEN 'ADD'.
NUM3 = NUM1 + NUM2.
when 'EXIT'.
LEAVE PROGRAM.
ENDCASE.
ENDMODULE.                 " USER_COMMAND_0100  INPUT
*&      Module  CNUM1  INPUT
      text
MODULE CNUM1 INPUT.
ENDMODULE.                 " CNUM1  INPUT

Answer 1

Hi,
  ON Screen the data type of screen fields are diffrent than the data type declared in Report.
Check it once.
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