One of the keys on my laptop crashed …?

I have a Dell XPS M1210. If one of the keys fell, but the rubber thingie is still in force, so that the work is key should I bother buying a new one? If so, does anyone know where I could buy it? It is the "8" key, then it is not surprising that necessary but if anyone knows where I could get a replacement I appreciate it. Thank you!

Sometimes they snap back in .. I never tried to replace a portable keyboard, but you should ask your laptop over the company.