This example is adapted from W.B.KHAN, figure 5-10, page 114. 
I called the input file: sign-in and the output file: sign-out.

I made appropriate changes to input negative values. 

The new version is called sign.cbl. I placed this example, 
and its input data file called sign.in in the following directory:

     ~jclevin/HTML/COURSE/COBOL/EXAMPLE

You may copy this example and the corresponding input data file
to your account, compile it and run it.

1. INPUT RECORD:

Using signed input data (+1200 instead of 01200), I declared the field 
employee-rate-in (to accept negative values):

       02   employee-rate-in  pic S9(2)v99  sign is leading separate character.

2. OUTPUT RECORD:

I changed the declaration of the output record to include a sign for 
the rate-out and gross-pay:

        02      employee-rate-out       pic -9(2).99.
        02      gross-pay-out           pic -9(4).99.


3. WORKING STORAGE:

I made the following changes to the working storage area:

02 special-value  pic S9(5)v99 value -15.00 sign is leading separate character.
02 ws-gross-pay    pic S9(5)v99 value 0   sign is leading separate character.
02 ws-overtime-pay pic S9(5)v99 value 0 sign is leading separate character.
02 ws-overtime-rate   pic S9(5)v99 value 0  sign is leading separate character.

4. CHECKING FOR NEGATIVE VALUES:

I did the following checks for negative values (special-value is set 
to the value: -15):

        if employee-rate-in is negative
                display ws-gross-pay.
        if employee-rate-in is equal to special-value
                display ws-gross-pay.

I guess the most important aspect here was to specify a sign as leading, 
separate character, in declaring the data.

The next slides include:

* the program source code
* the input data file
* the program compile and execute commands

You can download them to your account by accessing these slides, then type:

* a backslash (\) to access the HTML document
* a (p) to save the file to your account.

Or you can copy the examples from the following directory:

      ~jclevin/HTML/COURSE/COBOL/EXAMPLE