Hi ,
If fields are not available at UI then please check you configuration which is calling from UI and add the fields to that configuration as suggested by Harish.
If still the fields are not visible at UI then check in
SPRO->CRM -> UI Framework -> UI Framework Definition -> Design Layer -> Deactivate Hiding of Fields.
Now your fields should be visible in UI.
Second for enabling and disabling the text field on the basis of check box you need to add one more line to get_p_field1 method as:-
when if_bsp_wd_model_setter_getter=>fp_server_event.
rv_value = 'submit'.
Now you can check in get_i method and make text field enable or disable.
Regards,
Kumar.