My macbook pro mid 2009 keyboard and trackpad is not working.

My macbook pro mid 2009 keyboard and trackpad is not working. it was working perfectly fine a week ago and it stopped. i tried using a external wireless mouse and keyboard but only the mouse will work!! They keyboard lights up when it is booting up but when i try to sign in, nothing types or the mouse wont work. i am fine if the mouse doesnt work because i can use an external one but can someone please help me?!