how to fix a keyboard

Generally these keys clip onto the carrier so if it is falling off the clip on either the bottom of the key or carrier has been broken.

As far as gluing goes it is not recommended as most people go crazy with the glue and make more problems than they cure but a very small amount of Supa Glue if used correctly will hold the key in place. I would recommend that when you try this to have the Note Books Keyboard upside down so that any excess glue runs back into the bottom of the key and not into the keyboard proper.

BUT BE VERY CAREFUL!

Col

you may wish to replace the keyboard yourself. it might be fairly easy. if it were me i think i would go see how much for a keyboard for my model. i use www.impactcomputers.com for my notebook parts and they will help if you email them with questions. if i could afford the keypad, i'd go to the toshiba website and see if they had service manual to download to show me the steps.
you'll need a flat well lighted surface where you can spreadout instruction sheets and notebook guts and not knock stuff off. also the screwdriver bits for your notebook, a grounded place to set parts and a way to keep yourself grounded. i use an off but plugged in pc chassis and touch the chassis if i am caught without my static strap...
go slowly. take picturs if you like that. i just tape the screws to the place on the instruction sheets where i took 'em off. watch for internal cables you may accidently pull off but all the internl cables will pretty much be 'zero insertion force' ones. so the problem will not be accidently pulling them off but forgetting to put them back on. study how they are folded/routed and do it the same way on reassembly. use a little flat eyeglass screwdriver to unlatch the zero insertion force latches.
a magnetic screwdriver really helpful.