Defines a line-edit with a drop-down list of values, in a stack-based layout.
COMBOBOX field-name [ , attribute-list ] ;
COLOR, COLOR WHERE, COMMENT, DEFAULT, DOWNSHIFT, FONTPITCH, HIDDEN, KEY, INCLUDE, INITIALIZER, ITEMS, JUSTIFY, NOT NULL, NOENTRY, QUERYEDITABLE, REQUIRED, SAMPLE, SCROLL, SIZEPOLICY, STYLE, UPSHIFT, TAG, TABINDEX, UNSORTABLE , UNSIZABLE , UNHIDABLE , UNMOVABLE, TITLE, VALIDATE LIKE.
Define the rendering and behavior of a combobox stack item, with a COMBOBOX element inside a STACK container.
For more details about this item type, see COMBOBOX item type.
COMBOBOX customer.city,
   ITEMS=((1,"Paris"),
          (2,"Madrid"),
          (3,"London"));
COMBOBOX customer.sector,
   REQUIRED,
   ITEMS=("SA","SB","SC");
COMBOBOX customer.state,
   NOT NULL,
   INITIALIZER=myinit;