Asterisk 1.2 voicemail

how do i reload voicemail module on asterisk 1.2 . calls do not go to voicemail

exten => s,1,Answer()
exten => s,n,Set(TIMEOUT(response) = 4)
exten => s,n,Background(icas-ivr)
exten => s,n,Voicemail(u6500)