Modal frame

[MisterKewl]

For my mod I use a frame to do some configuration stuff, and one of the things to configure is which icon to display for an action bar button. So I display the icon and an "Edit" button, which opens a second frame, where the user can choose another icon. My problem is, that while the icon-choosing frame is open, I want to prevent the user from closing the main configuration frame. Is that possible without coding some checks in the close-method of the main frame to see if the icon-choosing frame is open, maybe by making the icon-choosing frame modal or something ?

Thanx in advance.