A choice with text beside it. Radio buttons are combined to show a user a fixed set of choices from which only one can be selected.

• It must be an alphanumeric field of length 1.
• Radio buttons are defined through the RBnn input/output attribute, where nn = 01 to 99. The nn refers to the group that the radio button belongs to. The maximum number of radio buttons that may be defined for a function is 999.
• Identification must be either label (*LABEL) or no identification (*NOID). Label is the default.
• Within RDML the valid values for a radio button field are "1" for selected and " " for unselected. Use of other values may produce unpredictable results.
• When on a NPT screen a radio button is selected with a "/" or country-designated character (defined in the DC@OSVEROP *SELECTCHAR=x option) and unselected with a " ". This character is locked in at compile time for the best performance when executing.
• LANSA generated code handles the conversion between screen and RDML values for radio buttons (i.e. from "/" to "1" when selected).
• There are certain restrictions enforced when using and initializing radio buttons. One and only one radio button per group MUST be selected, or unpredictable results may occur.
• A new system value named *RADBUTTONSELECTED has been created to be used when testing the return value of a radio button field. Use of this system variable makes your RDML code "self-documenting".
• A radio button may only contain one of two values. Therefore the best way to test its value is to check if it is *EQ (equal) or *NE (not equal) to the selected value (*RADBUTTONSELECTED).
• To test if a radio button has been selected:

     BEGIN_LOOP
       REQUEST    FIELDS(#SCREEN)
           IF         COND('#RADIO01 *EQ *RADBUTTONSELECTED')
       MESSAGE    MSGTXT('Radio button 1 is selected')
           ENDIF
           IF         COND('#RADIO02 *NE *RADBUTTONSELECTED')
       MESSAGE    MSGTXT('Radio Button 2 is not selected')
           ENDIF
     END_LOOP
 

• The correct way to initialize radio button:

         CHANGE     FIELD(#RADIO1 #RADIO2 #RADIO3 
                      #RADIO4) TO(*NULL)
 
             CASE       OF_FIELD(#TAXRATE)
             WHEN       VALUE_IS('= 0')
             CHANGE     FIELD(#RADIO1) TO(*RADBUTTONSELECTED)
             WHEN       VALUE_IS('= 10')
             CHANGE     FIELD(#RADIO2) TO(*RADBUTTONSELECTED)
             WHEN       VALUE_IS('= 20')
             CHANGE     FIELD(#RADIO3) TO(*RADBUTTONSELECTED)
             WHEN       VALUE_IS('= 30')
             CHANGE     FIELD(#RADIO4) TO(*RADBUTTONSELECTED)
             ENDCASE