How to create Development Class in SAP R/3 4.7c and Netweaver?

Question

I follow some old notes on ABAP Development Class but I could not create a new Development Class. i.e. Stuck in creatinf a type group.  Please give some details on how to create a development class.  Thanks.
see the following stepa:
(A) Procedure for creating  a type group:
/nse80
1. Object Navigator> select Development class>(Enter your development class
   yFTGxxDEV
2. Double click on development class object types.
3. Type Group: zPTAxx1.
4. Click on the Create button at the bottom (4th one from the left).
5. Enter short text: zPTAxx1 type group.
6. Save>Enter your development class> click on diskette button to save the type group
7. Select Source Code tab and enter the following:
"An example type-pool statement containing types and constants
type-pool zxx1.  "zxx1 is a type pool. It is also known as a type group
types: zxx1_dollars(16)    type p decimals 2,
             zxx1_lira(16)          type p decimals 0.
constants:
       zxx1_warning_threshold type i value 5000,
       zxx1_amalgamation_date like sy-datum value '19970305'.
8. Select  Type Group from menubar
           a) Check
           b) Save
           c) Activate
9. Click the back button or F3 to exit.
10, Show  your type group to your teacher.
11. Go to ABAP editor and enter the following program:
"Calculations on date
report zxx_0914.
type-pools zxx1.                   "contains zxx1_amalgamation_date
data:    d1              like sy-datum,
            d2              like d1,
            num_days type p.
d1  = d2 = sy-datum.
subtract 1 from d1.
write / d1.                              "yesterday's date
d2+06 = '01'                         " first day of current months
subtract 1 from d2.
write / d2.                           " last day of previous month
num_days = sy-datum - zxx1_amalgamation_date.
write / num_days.                " number of days since amalgamation
11. Double click zxx1 from the type-pool statement to see the type group.
12. Follow lab1 procedure and run your program
(B) Run an ABAP program using field symbol ( i.e. pointer)
report zxx_lab6.
data  f1(3)  value   'ABC'.          "Step 1 Define a variable
field-symbols <f>.                     "Step 2 Define a pointer variable ( it only stores address)
assign f1 to <f>.                        "Step3 Initialize the pointer variable with an address
write <f>.                                    "Step4 Now you can use <f> in place of f1
write / f1.                                      " (same as write f1 )  
<f> = 'xyz'.                                   " Assign a new value to f1
write <f>.
write / f1.

Answer 1

This is not the way to create a new development class.
Follow this steps to create a development class:
http://sap.mis.cmich.edu/abap4/knowbase/Create-Dev-Class.pdf
Regards,
Naimesh Patel