Adding dependency on another program

[zewari]

Hey folks, I'm not sure what the technically appropriate way to define this behavior is, so please bare with me. Some programs have a way of establishing a dependency with other programs such that if one attempts to uninstall the required program, a pop-up appears that would inform the user about the dependent programs that would not be able to function properly.

For example, assume program A requires program B to be installed. If the user attempts to uninstall B while A is still installed, a notice advises the user to either uninstall A first or at least lets them know that A will no longer work. If possible, I would like the uninstallation of B to force the uninstallation of A prior to B's removal. Is this doable, NSIS gurus?