当我们点击自定义时如何关闭JCombobox的下拉列表？

I have a JCombobox in which when I select any one from drop down list of JCombobox ,the selected item is opening but when I click on "Custom" among one of the drop down list I have to open a daiolg ,here daiolg is opening but drop down list is not closing I want to hide the drop down when I click on Custom. here is my sample code....I have a JCombobox in which when I select any o