I'm a new Java user and I'm currently working on a program and need a way to enable a ComboBox when a CheckBox is selected. The ComboBox must also be disabled unless that CheckBox is checked. 

I'm trying to have it so the ComboBox is disabled (and basically darkened out and not able to be used) unless that corresponding CheckBox is clicked, and I'm trying to use if statements to get this done but not sure what to do next.

```
        if (chkBuildCourse.isSelected())
        {
            instructorIsComboBox.
        }

        else if (chkNewInstructor.isSelected())
        {
            addInstructorComboBox.
        }

```