Example Get a ComboBox form field view and fill the item list

Form Specification File:

DATABASE FORMONLY
LAYOUT
GRID
{
  Airport:  [cb01                 ]
}
END
END
ATTRIBUTES
COMBOBOX cb01 = FORMONLY.airport TYPE CHAR;
END

Program File:

MAIN
  DEFINE cb ui.ComboBox
  DEFINE airport CHAR(3)
  OPEN FORM f1 FROM "combobox"
  DISPLAY FORM f1
  LET cb = ui.ComboBox.forName("formonly.airport")
  IF cb IS NULL THEN
     ERROR "Form field not found in current form"
     EXIT PROGRAM
  END IF
  CALL cb.clear()
  CALL cb.addItem("CDG", "Paris-Charles de Gaulle, France")
  CALL cb.addItem("LCY", "London-City Airport, UK")
  CALL cb.addItem("LHR", "London-Heathrow, UK")
  CALL cb.addItem("FRA", "Frankfurt Airport, Germany")
  IF cb.getIndexOf("SFO") == 0 THEN
     CALL cb.addItem("SFO", "San Francisco International Airport, CA" )
  END IF
  INPUT BY NAME airport
END MAIN