Touchpad not working,Toshiba Satellite P75-A7100


Today i am facing a lot of problem.I turned my laptopand the the touchpad did'nt respond i tried using f5 for my toshiba laptop,still its not working.but suddenly i discovered it works with when i click rmb+tochpad,but it causes several problems while using my browser(internet)-like copying wrong texts,selecting wrong options etc,pls tell me what 2 do i m really worried.
Thaan you,for ur answers