Question: couldn't remove multile files???

[gonboy]

suggest:

1 - select Project File Tree-> Multile Files(SHIFT + left Click Mouse to select),
     right mouse to remove files?

     why remove only one file???
     and the other pop menu to make one file only!
2 - How to set Tools to select that files which I selected multile files?
     i couldn't find the List of available built-ins to do it
     (eg: $(ACTIVE_EDITOR_FILENAME,...))