How to make a Select Option Mandatory.

Question

hi,
In my requirement , I'm supposed to make a Job Code Key mandatory, if if a selection Drop down is clicked.
ie., if for key  Employee Type = FullTime, PT, Students.(Drop Down)
when Students key is clicked, Job Key option should be made mandatory, This madate is happening, but when I go back and selct FT employee, Job key mandate is not disappearing.
plz let me know.
Thank Q.
Rohini.

Answer 1

Hi,
At the Selection screen.
I gave code like
fill the list box of employee type
  param = 'P_EMPTYP'.
  value-key = c_1.
  value-text = c_ft.
append the values to table values .
  APPEND value TO values.
  value-key = c_2.
  value-text = c_pt.
append the values to table values .
  APPEND value TO values.
  value-key = c_3.
  value-text = c_ptft.
append the values to table values .
  APPEND value TO values.
  value-key = c_4.
  value-text = c_students.
append the values to table values .
  APPEND value TO values.
calling the FM to set the values
  CALL FUNCTION 'VRM_SET_VALUES'
    EXPORTING
      id     = param
      values = values.
  param1 = 'P_ESTAT'.
  REFRESH values1.
  value1-key = c_1.
  value1-text = text-087.
  APPEND value1 TO values1.
  value1-key = c_2.
  value1-text = text-088.
  APPEND value1 TO values1.
  CALL FUNCTION 'VRM_SET_VALUES'
    EXPORTING
      id     = param1
      values = values1.
IF p_emptyp = 'Students' .
IF p_emptyp = c_4 .
  LOOP AT SCREEN .
    IF screen-name = 'S_CODE-LOW' .
       screen-required = 1 .
        MODIFY SCREEN .
    ENDIF .
   ENDLOOP .
  ENDIF .
Its wrking well here
,I do F8 n select Students there, Its shows Job Key (s-code) as mandate.
but when i come back Output selection screen n click for Full Time employee,
it is also asking for Job key, for it not not supposed to.
Can u plz correct me.
Thank Q.
Rohini.