Ribbon: Combo - read only

Suite and Optimus Suite 5
#1

How can the combo inside of the ribbon bar be set to read only?

                      {type:'buttonCombo', id:'teset', width:120, items: [
                          {value:"1", text: "ABC", selected: true},
                          {value:"2", text: "DEF"},
                          {value:"3", text: "HIJ"}
                      ]}
#2

Oh wow…this works:

 {type:'buttonCombo', id:'teset', width:120, readonly:'true', items: [
                          {value:"1", text: "ABC", selected: true},
                          {value:"2", text: "DEF"},
                          {value:"3", text: "HIJ"}
  ]}