I'm creating a new custom property editor and am trying to use the showModal function to popup a dialog for user input, however, I can't figure out how to handle the OK and cancel button click.

Basically, I just want to call a js function when the user fills out or closes the dialog and be able to handle the ok or cancel click.

Does anyone know how to do this?  I've been able to successfully display the dialog and can post to my custom property editor, but can't figure out this last piece.
Are there variables in the onRemoving function that can indicate a cancel or ok button click?

$u.Sys.WindowManager.getInstance().showModal({
            id: "test",
            title: "Test",
            isGlobal: false,
            forceContentInIFrame: true,
            modalClass: "define-section",
            removeOnHide: false,
            contentUrl: "/Umbraco/myPropertyEditor",
            showClose: true
)};

Thanks for your help